Accurizing the Factory Lever: Part 1

Bolt action rifles, lever action, pump action, self loading rifles and other miscellaneous longarms.

Accurizing the Factory Lever: Part 1

Post by in2anity » 29 May 2019, 2:57 pm

As promised (to a couple of members), here's an article I've been working for a while from my blog. It really should probably be in the gunsmithing section, but I figure more lever-gun laymen may see it here. One day there will be a part 2, but that's still a long way off. Enjoy.

The purpose of this article is to give an entry-level guide to some of the (easier) alterations you can make to improve a lever action rifle’s inherent accuracy. In truth there’s virtually an endless list of improvements the tinkerer can make. Nonetheless the return on effort somewhat diminishes following the more significant modifications. I’ll therefore focus on these fundamental (and essentially simpler) improvements. Most of my information for this article comes from the rather famous, yet sadly out of print book “Accurizing The Factory Rifle – M. L. McPherson.” And to quote Paco Kelly’s Leverguns:

“Gaining accuracy in a leveraction rifle is really not much different than doing it in a bolt action. The principles are the same. There is no mystery, it is just that most folks take if for granted that 3 to 5 inches at 100 yards is normal and you have to live with it. That is utter nonsense….first of all on today’s market there is not one brand of lever action, one style, or one make that won’t generally shoot into less than 2 inches with the right ammo. Some few individual guns (lemons) may go into larger groups…but bolt actions have the same problems with the unusual stinker in a group.”

The Problem with Bedding

As the barrel and action heat and/or any timber warps, most factory lever action rifles exhibit a wandering point of impact (poi). I’ve had accurate lever action rifles which were profoundly accurate, but only for those opening cold-bore shots. After that, the poi rather dramatically moved as the rifle heated up, usually downward vertically. This is what is often referred to as “vertical stringing”, and is really common for levers.

string.jpg
Typical full-power 50m group showing “vertical stringing”. From cold, the group starts tight, but inevitably wanders after repeated shots.
string.jpg (903.01 KiB) Viewed 8473 times


I’ve had other lever guns that also seemed to cluster nicely, but then seemed to throw a “flyer”, often more laterally than vertically. I’ll label this “lateral stringing”. Both are symptomatic of different bedding issues.

lateral.jpg
Extract from Accurizing The Factory Rifle – M. L. McPherson
lateral.jpg (1.51 MiB) Viewed 8473 times


Vertical stringing usually stems from forend stresses. “Flyers” may well indicate buttstock-to-receiver bedding issues. Using your favourite load, a valuable test is to obtain a good sense of how your gun behaves (as the barrel and action heats). Then, completely remove your forend and carry out the same test to see how your groups change. This can be a little tricky, but is achievable by balancing the receiver on a front rest. With a bit of luck, your poi will be noticeably more stable (without the forend); then you know your issues are coming from the forend. If not, then it’s reasonable to presume your issues are more likely to reside in the buttstock.

Part 1: Forend Bedding

To quote M.L.McPherson “Obviously, any system that places wood (or almost any synthetic material) in direct contact with both the receiver and barrel offers the potential for the following things to induce stress between the forend and the barrel-receiver system: changes in barrel temperature, due to shooting or atmospheric temperature; variation in stock size and shape, due to changes in atmospheric humidity”

A lever action rifle leaves the factory with a tightly fitted forend to receiver and barrel. As a result, as the barrel heats, the barrel has a tendency to expand and move away from the timber, thus resulting in the aforementioned wandering poi. The wandering direction can seem odd, however remember that any barrel taper will impact poi characteristics. Furthermore, wood-to-metal contact with respect to the receiver and frontal forend capture are subject to any timber warpage over time, also possibly affecting any inherent stresses on the barrel. The basic premise of accurizing the forend is to relieve these stresses.

Firstly, we will remove a little material between the forend and the receiver. We will then replace this material with a gel-type epoxy bedding agent. BROWNELLS ACRAGLAS GEL® is the perfect product for this. The traditional, less viscous, BROWNELLS ACRAGLAS® can be problematic (when bedding the vertical surfaces). From personal experience, I strongly recommend using a gel-style bedding agent for the following step.

gel.jpg
Use a gel-type epoxy bedding agent
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Remove the magazine tube for the entirety of Part 1. Using a fine toothed file, carefully file away a small amount of material where it keys into the receiver. This will be replaced by our bedding agent, providing the perfect fit between the forend and receiver (and removing any problematic wood-to-metal contact). After making these reliefs and reassembling, the entire forend should be able to (ever so slightly) rock back and forth.

unrelieved.jpg
Unrelieved
unrelieved.jpg (756.01 KiB) Viewed 8473 times


relieved.jpg
Relieved – just a very light sanding on the bearing surfaces. Notice I haven’t altered the upper flats as this does not make contact with the action – only the lower flat surfaces and a tiny amount on the vertical.
relieved.jpg (734.33 KiB) Viewed 8473 times


McPherson takes this a step further, and actually suggests adding a layer of RTV silicone here (between the new glass and receiver), however the wider consensus is that the simple glass bed here will suffice.

Ensure that the keyed portion of the forend that enters into the front of the receiver is clean. If necessary, use alcohol or carburetor cleaner to clean any oil from the wood. Ensure any excess solvent has evaporated, possibly use a portable hair dryer to heat the wood and evaporate the remaining solvent.

Apply multiple coats of release agent under the barrel in front of the receiver and to the areas of the receiver face itself that might make contact with the forend. Apply quality masking tape around the perimeter of the receiver, and around the adjacent perimeter of the timber forend (to protect the finish). Dam the magazine feed hole in the receiver with modelling clay, mask over the top of this. Also dam the magazine channel in the forend (preventing any bedding agent from flowing into the magazine channel). As a precaution I also dammed the narrow upward pointed channels either side of the barrel on the receiver. Basically, as neatly as possible, mask any timber and metal that you don’t want bedding agent to bind to; the only exposed area without tape and/or release agent should be the timber that keys into the receiver.

foendReady.jpg
Forend ready for bedding
foendReady.jpg (887.89 KiB) Viewed 8473 times


actionPlugged.jpg
Feed tube plugged, we still need to mask and coat the action here with release agent
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Mix a small batch of gel-type bedding agent. Since this material will be visible on the finished rifle, add a dab of colorant to match the hue of the forend. Remember a little bit of colour goes a long way.

colarant.jpg
Go easy on the colarant – a little bit goes a long way
colarant.jpg (1.26 MiB) Viewed 8473 times


Apply the bedding agent to the keying portion of the forend (the relieved perimeter that you just cleaned). Be sure to get a sufficient coating to adequately cover the surfaces that key into the receiver. Reassemble the forend (excluding the magazine tube). Wipe away the excess gel that extrudes out with a damp cloth.

coated.jpg
More gel is better - we can always remove later
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extruded.jpg
You want enough gel so it extrudes out like this
extruded.jpg (1.12 MiB) Viewed 8473 times


wiped.jpg
Excess gel can simply be wiped away
wiped.jpg (1.26 MiB) Viewed 8473 times


Allow to dry for 24 hours with the magazine removed and barrel and receiver supported. Do not allow the rifle to rest on the forend while the epoxy hardens, the rifle should be right side up and horizontal during this process. Once the epoxy is set the forend should come apart fairly easily.

Upon disassembly, chip away any gel that has spread up onto the upper flats surround the magazine channel - this area is not a bearing surface and thus should be kept that way. Your forend should now be a perfect fit that should facilitate easy disassembly and reassembly. This is the foundation of the next (most crucial) step; RTV silicone bedding the barrel channel.

bed.jpg
Only the lower bearing surfaces should have the glass bed.
bed.jpg (823.06 KiB) Viewed 8473 times


Again to paraphrase McPherson: I can recommend laying a bead of silicone down the barrel channel. Assuming the forend is bedded at the receiver and at the forend attachment hanger (as described in the previous sub-sections), this RTV layer can aid in preventing resonation of vibrations between the forend and barrel. Further, it performs as a soft cushiony gasket which will not produce or allow significant stressing between the forend and the barrel as the barrel and action heat.. On two-piece stocked rifles (including tubular magazine models), black RTV (Room Temperature Vulcanizing) silicone is the magic elixir for bedding the forend to the barrel and receiver. DO NOT, I REPEAT DO NOT use a traditional acetic cure RTV silicone for this purpose. Acetic cure will rust through your barrel faster than a fat kid with a box of cupcakes. Instead look for electronics grade RTV, it’s usually acid free. Permatex make one called “ULTRA BLACK”; that’s the one I used with good success.

permatex.png
Room Temperature Vulcanizing silicone
permatex.png (427.49 KiB) Viewed 8473 times


Before the application of the RTV silicone be doubly certain to apply a good thick coating of release agent to the barrel and receiver — failure to do this will almost positively guarantee that you will not be able to separate the forend from the barreled-action without destroying one or the other! This product does exactly what the name implies — it vulcanizes, bonding with tremendous tenacity and strength.

It is important to ensure that the barrel channel clears the barrel along its entire length. With a dowel that closely matches your barrel profile sand away the barrel channel until there is sufficient clearance to slip a playing card between the forend and the barrel channel with the forend normally installed. The card should not bind at any point. I achieved this by buying some 25mm dowel that matched the diameter of the barrel at its thickest point next to the receiver. I carefully turned the dowel down using 80 grit paper (and a cordless drill!) to closely match my taper. I then glued 80 grit onto this piece of tapered dowel, creating a sanding tool that near-exactly matched my barrel channel profile. As specified above, I then sanded out the channel just enough to (after reassembly) slide a few pieces of paper under the barrel with no pinch points.

sanding.jpg
The poor man’s lathe!
sanding.jpg (2.77 MiB) Viewed 8473 times


sanded.jpg
Keep sanding until barrel profile is matched
sanded.jpg (2.57 MiB) Viewed 8473 times


glued.jpg
I attached sandpaper on using epoxy
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preppedForend.jpg
Sanded barrel channel
preppedForend.jpg (1.26 MiB) Viewed 8473 times


floated.jpg
Sufficient clearance to slip a playing card between the forend and the barrel channel with the forend normally installed
floated.jpg (1.39 MiB) Viewed 8473 times


Apply a good thick coating of release agent to the barrel, especially the underside where the silicone is sure to make contact. Mask the outside areas of the forend parallel to the (newly) sanded channel - the masking should be neat and precise as this area will obviously be visible. Liberally apply release agent to the front of the receiver where the silicone could possibly extrude.

Run a large pea-sized bead of silicone down both sides of the channel (where previously sanded), enough so that a bead silicone will extrude  out either side out along the barrel upon reassembly.

bead.jpg
Better too much than too little here – we will trim away any excess silicone once green
bead.jpg (1.45 MiB) Viewed 8473 times


With the magazine tube still removed, reassemble the forend and tighten up the screws. Invert the rifle and support in the horizontal position and allow the RTV sufficient time to cure to a soft rubbery consistency, about six to twelve hours. At this time the RTV is still "green", it has not developed its full strength.

extrudedSilicone.jpg
A little extrusion of silicone is what we are aiming for
extrudedSilicone.jpg (1007.57 KiB) Viewed 8473 times


Use a single-edge razor blade or an X-acto knife (or similar tool) to carefully trim away the RTV that has extruded from between the forend and the receiver. If you applied release agent properly, the RTV will not stick too tenaciously to the exposed wood or metal surfaces. You should not have any trouble cutting and peeling the extruded RTV away from the barrel and forend.

trimmed.jpg
For best results lay the blade at about a fifteen degree (15°) angle to the edge of the wood. The goal is to cut the RTV layer off flush at the wood side but deeper at the barrel side.
trimmed.jpg (1.23 MiB) Viewed 8473 times


cured.jpg
The RTV bedded channel after curing and trimming
cured.jpg (896.71 KiB) Viewed 8473 times


topDown.jpg
Not perfect, but pretty good. Especially on older rifles imperfections are less noticeable.
topDown.jpg (1.73 MiB) Viewed 8473 times


That concludes Part 1. At this point I suggest shooting some groups to get a clear idea of how your rifle groups. It may be sufficient to finish your alterations here (and skip Part 2 altogether). It really depends on the nature and to what degree you are chasing accuracy.

cluster2.jpg
Following the bedding procedure, here are 9 shots in a row WITHOUT pausing between targets. 21grs AR2207/H4198 under a 150gr (~1900fps). No more vertical stringing.
cluster2.jpg (1.94 MiB) Viewed 8038 times


finished.jpg
BTW the above work was carried out on JM era Marlin 30AS manufactured in 1996
finished.jpg (1.61 MiB) Viewed 8463 times


200mGroup.jpg
200m 12-shot group - for a 30/30 lever, a bit over 4" is pretty outstanding for such a long string of shots.
200mGroup.jpg (330.63 KiB) Viewed 8463 times
Last edited by in2anity on 21 Jun 2019, 2:45 pm, edited 7 times in total.
At what point does lack of maintenance become patina?
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Re: Accurizing the Factory Lever: Part 1

Post by GQshayne » 29 May 2019, 5:11 pm

Interesting. I have never considered this before, as my lever gun has no need for any great accuracy, given its usage as a short range moving target field rifle. However, my second hand to me, FN Browning BLR, had a couple of things that caught my attention when I removed the stock from it. Yep, looks like it has been bedded at the forend and slightly at the receiver end as well. I doubt this was done at the factory, but you never know.

I have sighted it in when I fitted the scope to it, but I forget what sort of group it shot.
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Re: Accurizing the Factory Lever: Part 1

Post by bigrich » 29 May 2019, 5:46 pm

interesting post in2anity . this confirms a view theorys with my 357 marlin. it has shot some really good groups in the past , but it's been a bit off lately . something that i have done different was to tighten the band around the barrel and magazine tube tighter than it was. when it was shooting well before you could grab the magazine tube and wiggle it side to side under the barrel . i definately get the vertical string in my groups. the fit in the wood to metal on my marlin is quite good compared to some i've seen . the silicone between the forend and barrel has me thinking. and i have a tube of that ultra black silicone in the shed . good informative post. thanks for that. i would like to see more of this kind of thing on this forum :thumbsup:

:drinks: :drinks: :thumbsup:
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Re: Accurizing the Factory Lever: Part 1

Post by Wm.Traynor » 29 May 2019, 7:34 pm

Wow! What a job of work you've done mate :clap: :clap: :clap: I will be all over this with my Mossberg. Thank you very much :thumbsup:
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Re: Accurizing the Factory Lever: Part 1

Post by Blr243 » 29 May 2019, 8:05 pm

Because of the bolt lug type lock up and floating barrel on my blr I never was concerned about lack of accuracy. The factory trigger was lacking so I had a Smith work on it and was told there’s only so much you can do with those triggers. I recently was so fed up with the trigger that I switched completely to a sauer 100 bolt gun..... thanks for taking the time and for the great info you have posted ....it’s very useful and very good reference material that I’m sure a lot of us can benefit from.
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Re: Accurizing the Factory Lever: Part 1

Post by marksman » 29 May 2019, 8:08 pm

awesome write up :clap: :clap: :clap: :clap: :clap:
I have never bothered with this type of thing on a lever but you have got my interest going :drinks:
cant wait for the other parts :drinks:
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Re: Accurizing the Factory Lever: Part 1

Post by in2anity » 30 May 2019, 8:37 am

GQshayne wrote:Interesting. I have never considered this before, as my lever gun has no need for any great accuracy, given its usage as a short range moving target field rifle. However, my second hand to me, FN Browning BLR, had a couple of things that caught my attention when I removed the stock from it. Yep, looks like it has been bedded at the forend and slightly at the receiver end as well. I doubt this was done at the factory, but you never know.

I have sighted it in when I fitted the scope to it, but I forget what sort of group it shot.


Right - blrs suffer the exact same fate. In fact, McPherson largely bundles the blr and savage 99 (among others) into the same set of instructions for RTV bedding. There was a funny line in there somewhere about the early blrs being an absolute travesty when it came to nasty forend tensions, i'll see if i can dig it out...
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Re: Accurizing the Factory Lever: Part 1

Post by in2anity » 30 May 2019, 8:40 am

Wm.Traynor wrote:Wow! What a job of work you've done mate :clap: :clap: :clap: I will be all over this with my Mossberg. Thank you very much :thumbsup:

YW Wm - it's good to start on something a bit cheaper i reckon :thumbsup:
Last edited by in2anity on 04 Jun 2019, 8:02 am, edited 1 time in total.
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Re: Accurizing the Factory Lever: Part 1

Post by in2anity » 30 May 2019, 8:42 am

Blr243 wrote:Because of the bolt lug type lock up and floating barrel on my blr I never was concerned about lack of accuracy. The factory trigger was lacking so I had a Smith work on it and was told there’s only so much you can do with those triggers. I recently was so fed up with the trigger that I switched completely to a sauer 100 bolt gun..... thanks for taking the time and for the great info you have posted ....it’s very useful and very good reference material that I’m sure a lot of us can benefit from.


Yeah the blr and the henry lr are based on the winchester 88 rack-and-pinion design - very difficult to safely lighten the trigger. That's by far my biggest bug-bear with those rifles, hence why I stick with traditional lever guns.
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Re: Accurizing the Factory Lever: Part 1

Post by in2anity » 30 May 2019, 9:37 am

bigrich wrote:interesting post in2anity . this confirms a view theorys with my 357 marlin. it has shot some really good groups in the past , but it's been a bit off lately . something that i have done different was to tighten the band around the barrel and magazine tube tighter than it was. when it was shooting well before you could grab the magazine tube and wiggle it side to side under the barrel . i definately get the vertical string in my groups. the fit in the wood to metal on my marlin is quite good compared to some i've seen . the silicone between the forend and barrel has me thinking. and i have a tube of that ultra black silicone in the shed . good informative post. thanks for that. i would like to see more of this kind of thing on this forum :thumbsup:

:drinks: :drinks: :thumbsup:


I had a double-banded 30/30 at one time - I actually relieved the timber under the band, then re-finished with tung oil. I believe this helped with consistency (a little). With respect specifically to barrel bands, McPherson talked about lapping the bands where they contacted the barrel. The idea being the pressure should be as concentric as possible.

With respect to buttstock to receiver bedding - I get the impression that this is more applicable to older rifles, where the tapered tang bolt is perhaps no longer tight and load-bearing, or perhaps the timber has changed a bit under the tang over time - I think newer guns should be pretty good in these areas (in theory).

:drinks:
Last edited by in2anity on 30 May 2019, 11:27 am, edited 2 times in total.
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Re: Accurizing the Factory Lever: Part 1

Post by wrenchman » 30 May 2019, 9:53 am

i do have to say this was a good post and a good read
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Re: Accurizing the Factory Lever: Part 1

Post by GQshayne » 30 May 2019, 5:47 pm

Blr243 wrote:Because of the bolt lug type lock up and floating barrel on my blr I never was concerned about lack of accuracy. The factory trigger was lacking so I had a Smith work on it and was told there’s only so much you can do with those triggers. I recently was so fed up with the trigger that I switched completely to a sauer 100 bolt gun..... thanks for taking the time and for the great info you have posted ....it’s very useful and very good reference material that I’m sure a lot of us can benefit from.


They are notorious for being heavy, and also a tricky job for a gunsmith - some are better than others at it. Some smiths won't touch them. My cousin has a Mod81 BLR and the trigger has come up nice after some work. My original Fabrique Nationale BLR though is pretty damn good - no complaints from me on the trigger. Side by side I reckon you can see why they are sought after.

What model do you have???
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Re: Accurizing the Factory Lever: Part 1

Post by in2anity » 20 Jun 2019, 8:45 am

For those of you still interested, I finally made some time to test the RTV bedded 30AS in a controlled 50m environment. I took 9 rounds to the range. Here are those 9 shots in a row without pausing between targets:

IMG_9077.jpg
30/30 50m group; 21gr AR2207 under a 150gr (~1900fps)
IMG_9077.jpg (1.94 MiB) Viewed 8118 times


Interestingly, I did not crimp these loads. But neck tension is tight with the Hornady die (unlike the Lee die). I'd say at least -0.003". Yes, the poi shifts a little, but importantly the vertical stringing has now been eliminated. :drinks:
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Re: Accurizing the Factory Lever: Part 1

Post by Wm.Traynor » 20 Jun 2019, 9:45 am

OMG mate!!! That is Terrific :clap: :clap: :clap:
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Re: Accurizing the Factory Lever: Part 1

Post by GQshayne » 20 Jun 2019, 7:24 pm

Well done, nice job.
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Re: Accurizing the Factory Lever: Part 1

Post by Bodster » 08 Dec 2022, 12:59 pm

Really interesting article , thank you. You refer to the application of "multiple coats of release agent". I'm absolute novice. Would appreciate you giving the product name.
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Re: Accurizing the Factory Lever: Part 1

Post by in2anity » 12 Dec 2022, 2:47 pm

Bodster wrote:Really interesting article , thank you. You refer to the application of "multiple coats of release agent". I'm absolute novice. Would appreciate you giving the product name.
Cheers

Bodster. I use the paint-on agent that comes in the Acraglas kits, per instructions. Alternatively, you may be able to use:
-Kiwi Shoe polish, neutral
-Hornady one shot lube, two coats
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Re: Accurizing the Factory Lever: Part 1

Post by GQshayne » 12 Dec 2022, 7:46 pm

I used a combination of shoe polish, and then a spray with silicone spray.
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