Powder weight

[colinbentley]

I am firing a Ruger 77 mark 2 using ADI powder AR 2209. According to reloading manuals loads for this should start at 37 grains but not to exceed 40 grains. I began at 37 and for a while stopped at 38 but recently had better groupings at 100 metres with 38.5, I am tempted to go to 39 grains but am a little concerned it is too close to the maximum. There are no visible danger signs at 38.5 (but I am no expert) Do the members consider it safe to go to 39 to see if that further improves accuracy ? Sorry forgot to mention the caliber is a 243 Winchester.

[bladeracer]

I am firing a Ruger 77 mark 2 using ADI powder AR 2209. According to reloading manuals loads for this should start at 37 grains but not to exceed 40 grains. I began at 37 and for a while stopped at 38 but recently had better groupings at 100 metres with 38.5, I am tempted to go to 39 grains but am a little concerned it is too close to the maximum. There are no visible danger signs at 38.5 (but I am no expert) Do the members consider it safe to go to 39 to see if that further improves accuracy ? Sorry forgot to mention the caliber is a 243 Winchester.

If it's not showing any pressure signs then it is safe to go further.
My normal load in the .204 is 30.0gn of AR2206H behind the 24gn NTX. That's 0.5gn above ADI's maximum but still no pressure signs. Accuracy gets better the harder I push it so I would go further, but 30.0gns is heaped above the case mouth already and I can't get any more in there. ADI list 29.5gn at 4423fps from a 24" barrel. I'm getting right around 4400fps from my 22" barrel so I think my pressures are in the same ballpark as ADI.

[bigfellascott]

Just keep an eye out for pressure signs as you approach or go over max recommended loads - I'm over by about a grain I think on one of my loads and no signs of pressure issues so far, but I do keep an eye on the fired brass to see if it's changed at all through the diff temps.
I would say that the max recommended are fairly safe if not a little on the conservative side but don't take my word for it use your own judgement to work out what is right for you and your outfit.

[duncan61]

you are using a 100gn pill I take it from the chart.I use 80gn for ,243 and 2208.goes great

[Mitch]

Keep going mate, no signs = all good.

[straightshooter]

colinbentley

It's not simply the powder weight that is important.
Go on the Hodgdon site and you will see a precise recipe which includes powder weight + projectile + COL and an indication of average chamber pressure for H4350=AR2209 in a 243.
Their recommended maximum should not be exceeded in any commercially made chamber.
As soon as you depart from their exact recipe, ie change bullet brand or COL or use in a match chamber, you in effect are on your own as far as safety is concerned due to the unpredictable effect the change may have on pressure.
It's not that the rifle will instantly blow up or that you might have to hammer the bolt open. What will happen with the repeated use of mild overloads is insidiously gradual and can range from short case life to locking lug set back.
Loads somewhat below published maximum won't have any of those problems and the difference in performance in the field will be imperceptible.
If you are inexperienced it is far wiser to use data that was developed under laboratory conditions by experienced technicians rather than follow the advice of anonymous internet commentators whose advice, often, isn't worth the paper it's written on.

[duncan61]

Good advice S/S I found when tuning my .243 that brands of bullets made more difference to point of impact than powder weight or powder type.I used 2205 in my .222 and had a situation where there was white gunk in the barrel after a few shots.I use 2208 and it burns clean as.Some barrels dont like some bullets so I would be getting that sorted before I was too concerned about a few grains of powder.

[bladeracer]

colinbentley

It's not simply the powder weight that is important.
Go on the Hodgdon site and you will see a precise recipe which includes powder weight + projectile + COL and an indication of average chamber pressure for H4350=AR2209 in a 243.
Their recommended maximum should not be exceeded in any commercially made chamber.
As soon as you depart from their exact recipe, ie change bullet brand or COL or use in a match chamber, you in effect are on your own as far as safety is concerned due to the unpredictable effect the change may have on pressure.
It's not that the rifle will instantly blow up or that you might have to hammer the bolt open. What will happen with the repeated use of mild overloads is insidiously gradual and can range from short case life to locking lug set back.
Loads somewhat below published maximum won't have any of those problems and the difference in performance in the field will be imperceptible.
If you are inexperienced it is far wiser to use data that was developed under laboratory conditions by experienced technicians rather than follow the advice of anonymous internet commentators whose advice, often, isn't worth the paper it's written on.

Just because you use more powder than was found to be the maximum in a specific rifle in a laboratory does not mean you are making "over loads".
If you are not seeing any pressure signs it is extremely unlikely you'll do any damage.
Every rifle produces different pressures even with identical ammunition. Some will exceed pressure limits before you reach maximum charges, some won't.

[colinbentley]

Thanks to everyone who took the time to offer advice.

[Gwion]

The problem with saying 'watch for pressure signs' is that not everyone knows what to look for and as such could be skating on thin ice, slowly damaging their firearm or risking catastrophic failure. Accurate loads can be found I. The low-mid powder range with attention to details.

[bladeracer]

The problem with saying 'watch for pressure signs' is that not everyone knows what to look for and as such could be skating on thin ice, slowly damaging their firearm or risking catastrophic failure. Accurate loads can be found I. The low-mid powder range with attention to details.

I agree with you, but if they never approach higher pressures how will they ever learn what to look for?
I also agree that rarely is there any reason to go anywhere near pressure signs. But in this case, he is finding better accuracy as he increases the charge, and he is still 1.5gn or 3.75% below listed maximum, so why shouldn't he continue developing the load?

[colinbentley]

I thought that powder grains were my problem so went to 39 grains only to discover that it made no difference to 38.5 grains. In fact I was most disappointed so thought to look elsewhere for my sloppy accuracy. I went back to square one and remeasured my bullet seating depth. Then set the bullet only 20 thou off the lands. problem overcome. Now shooting MOA , granted only 100 metres but I feel very proud to have overcome the problem. It's taken months to get there.I had made a miscalculation in the bullet seating depth. Dopey me.

[Gwion]

Well done. Problem solved!

[Oldbloke]

I thought that powder grains were my problem so went to 39 grains only to discover that it made no difference to 38.5 grains. In fact I was most disappointed so thought to look elsewhere for my sloppy accuracy. I went back to square one and remeasured my bullet seating depth. Then set the bullet only 20 thou off the lands. problem overcome. Now shooting MOA , granted only 100 metres but I feel very proud to have overcome the problem. It's taken months to get there.I had made a miscalculation in the bullet seating depth. Dopey me.

I'm far from expert but have consistently found the 20 to 25 thou off the lands results in about MOA.

[Chronos]

A general note about reloading is that often the more powder in the loads the bigger the groups get at 100 however at longer distances they groupings may be smaller. this is due to the overall velocity of the round and when or if it transcends supersonic. (not always just related to supersonic/subsonic). The amount of powder the case consumes is a big factor as well as soon as the powder is compressed this can throw things right off. So try to find a powder that fills the case.

PS Dont forget that COL is for that bullet only. I have gone through all the bullets I have and worked out what the COL is. Most I cant put in the magazine so have to resort to single shot loading if i want that precision. The hunter bullets get made to the max of the magazine.

groups get smaller at longer distances

Chronos

[bladeracer]

A general note about reloading is that often the more powder in the loads the bigger the groups get at 100 however at longer distances they groupings may be smaller. this is due to the overall velocity of the round and when or if it transcends supersonic. (not always just related to supersonic/subsonic). The amount of powder the case consumes is a big factor as well as soon as the powder is compressed this can throw things right off. So try to find a powder that fills the case.

PS Dont forget that COL is for that bullet only. I have gone through all the bullets I have and worked out what the COL is. Most I cant put in the magazine so have to resort to single shot loading if i want that precision. The hunter bullets get made to the max of the magazine.

It is impossible for groups to be smaller at longer ranges than they are at close ranges. Shooting is a cone shape originating from the bore of the rifle and increasing in diameter with range.
The only way I can envision such a thing is in very gusty winds, but the odds of getting a smaller long-range group would be very slim indeed.
Transition invariably opens groups up, it does not tighten the groups.

[Gwion]

A general note about reloading is that often the more powder in the loads the bigger the groups get at 100 however at longer distances they groupings may be smaller. this is due to the overall velocity of the round and when or if it transcends supersonic. (not always just related to supersonic/subsonic). The amount of powder the case consumes is a big factor as well as soon as the powder is compressed this can throw things right off. So try to find a powder that fills the case.

PS Dont forget that COL is for that bullet only. I have gone through all the bullets I have and worked out what the COL is. Most I cant put in the magazine so have to resort to single shot loading if i want that precision. The hunter bullets get made to the max of the magazine.

I'm also calling this as a shooting myth with not basis in scientific theory.

If your groups are out of whack at 100yds, they will be the angular measurement out of whack at any given distance down range, plus the effects of wind, etc.
The Huston Indoor Precision Shooting Project (google it or search the forum, it was discussed recently) plainly found that there is no such thing as a rifle/round that shoots better further out than closer in.

I have heard quite a few old and experienced shooter who claim that if a load isn't working, just increase powder weight. This is a very rudimentary and potentially dangerous practice, particularly when doled out at random to inexperienced re-loaders.
There are generally a few "accuracy nodes" for any given rifle and, in my view, the best way to find them is through comprehensive load development, not randomly jacking up charge weight. Best accuracy comes with consistent velocity, not necessarily higher velocity. Sometimes a long range hunter will sacrifice the most accurate node for one at a higher velocity for more lee-way when ranging a target but when you are talking about target shooting out further, it is a very consistent load and detailed D.O.P.E that gives the best results.

[bladeracer]

There are generally a few "accuracy nodes" for any given rifle and, in my view, the best way to find them is through comprehensive load development, not randomly jacking up charge weight. Best accuracy comes with consistent velocity, not necessarily higher velocity. Sometimes a long range hunter will sacrifice the most accurate node for one at a higher velocity for more lee-way when ranging a target but when you are talking about target shooting out further, it is a very consistent load and detailed D.O.P.E that gives the best results.

Consistent velocity is not a guarantee of accuracy.
That's what the Ladder Test is used for, to find the region where differences in charge weight have minimal difference on elevation impact despite different velocities.

[Gwion]

What you are referring to is the accuracy node. This is a balance of harmonics and consistent velocity. There is no way a load that does not have consistent velocity will provide a good water line elevation out @500yd and further.

You are looking for the area where charge weight has little effect on velocity while providing consistent harmonics.

http://precisionrifleblog.com/2012/07/1 ... r-testing/

ladder-test-velocity-results-for-coated-223-berger-77gr-otm-tactical-varget-h48951.jpg (139.51 KiB) Viewed 5184 times

[colinbentley]

God, you've lost me. Silly old bugger that I am thought it was just a case of put a bullet in the gun and squeeze the trigger. Taken me 12 years to understand headspace !Now you've totally confused me.

[Gwion]

God, you've lost me. Silly old bugger that I am thought it was just a case of put a bullet in the gun and squeeze the trigger. Taken me 12 years to understand headspace !Now you've totally confused me.

You'll be right, mate!
At least you got your seating depth sorted.

[bladeracer]

What you are referring to is the accuracy node. This is a balance of harmonics and consistent velocity. There is no way a load that does not have consistent velocity will provide a good water line elevation out @500yd and further.

You are looking for the area where charge weight has little effect on velocity while providing consistent harmonics.

http://precisionrifleblog.com/2012/07/1 ... r-testing/

ladder-test-velocity-results-for-coated-223-berger-77gr-otm-tactical-varget-h48951.jpg

I agree, but I wasn't aware we were discussing 500yd+ accuracy

[Gwion]

We were just discussing the myth that a load can shoot better at distance than at 100yds... Never going to happen in any real and verifiable sense. A load that is shooting 1moa with both vertical and horizontal dispersion at 100yd is not going to shoot 1/2 moa at 200yd, 300 or even 500yds. must be beer o'clock, i think.

[bigfellascott]

The problem with saying 'watch for pressure signs' is that not everyone knows what to look for and as such could be skating on thin ice, slowly damaging their firearm or risking catastrophic failure. Accurate loads can be found I. The low-mid powder range with attention to details.

They shouldn't be reloading if they don't know the basics hey. Any half decent reloading manual will show you what to look for in regards to pressure signs and how to reload safely, if they haven't got one of those I guess they will get what they get in the way of results good or bad.

And the other thing you will notice about different reloading manuals and information re loads and max/min is they all vary with the same powder so best thing one can do is reload with a view to keeping an eye out for diff pressure signs that will be the best indicator if one is getting into dangerous territory for their particular firearm or not.

[Gwion]

The problem with saying 'watch for pressure signs' is that not everyone knows what to look for and as such could be skating on thin ice, slowly damaging their firearm or risking catastrophic failure. Accurate loads can be found I. The low-mid powder range with attention to details.

They shouldn't be reloading if they don't know the basics hey. Any half decent reloading manual will show you what to look for in regards to pressure signs and how to reload safely, if they haven't got one of those I guess they will get what they get in the way of results good or bad.

And the other thing you will notice about different reloading manuals and information re loads and max/min is they all vary with the same powder so best thing one can do is reload with a view to keeping an eye out for diff pressure signs that will be the best indicator if one is getting into dangerous territory for their particular firearm or not.

Yeah. Only thing with just reading a manual is that they are not all written in a way that makes sense to everyone. I had to read 3 and spend a good 6 months rehashing and pushing up the top end of powder loads before i started getting an idea exactly what pressure signs were. I'd like to see a manual with a full chapter devoted to pressure and detailed pictorials of what these different "signs" look like. I tried to start a thread on it to get some more experienced examples with pics and what not but it kind'a fell on its head.

A classic example is that most manuals refer to flattened or cratered primers but a lot of people claim that cratered primers are not a good indication. It's pretty obvious when your primer is well flattened, though. Just wonder how many people jump into reloading and never even look at the cases but just the groups!??!

[Oldbloke]

This looks like a good site about pressure signs.

http://www.massreloading.com/reading_pr ... signs.html

I got an idea. I'm shooting all my groups at 300 meters then swap the target for the 100 mtr targets. I'll win a few comps that way fro sure.

[Gwion]

Great link, OB! Thanks

[Oldbloke]

FIGJAM!

[colinbentley]

My ex wife was right when she said I needed to put it in deeper !!!!!!!!!!!

[bigfellascott]

The problem with saying 'watch for pressure signs' is that not everyone knows what to look for and as such could be skating on thin ice, slowly damaging their firearm or risking catastrophic failure. Accurate loads can be found I. The low-mid powder range with attention to details.

They shouldn't be reloading if they don't know the basics hey. Any half decent reloading manual will show you what to look for in regards to pressure signs and how to reload safely, if they haven't got one of those I guess they will get what they get in the way of results good or bad.

And the other thing you will notice about different reloading manuals and information re loads and max/min is they all vary with the same powder so best thing one can do is reload with a view to keeping an eye out for diff pressure signs that will be the best indicator if one is getting into dangerous territory for their particular firearm or not.

Yeah. Only thing with just reading a manual is that they are not all written in a way that makes sense to everyone. I had to read 3 and spend a good 6 months rehashing and pushing up the top end of powder loads before i started getting an idea exactly what pressure signs were. I'd like to see a manual with a full chapter devoted to pressure and detailed pictorials of what these different "signs" look like. I tried to start a thread on it to get some more experienced examples with pics and what not but it kind'a fell on its head.

A classic example is that most manuals refer to flattened or cratered primers but a lot of people claim that cratered primers are not a good indication. It's pretty obvious when your primer is well flattened, though. Just wonder how many people jump into reloading and never even look at the cases but just the groups!??!

Yeah she's a learning curb alright but with todays internet access it's a darn sight easier than when I started (I used Nick Harveys reloading Manual) and read it as best I could and just got going and soon worked out what was what but can't say I really ever read much about pressure signs (I figured if I stayed within the min/max I would be fine and I was and later on I pushed the boundaries to see what was what and it was fine for the most part (had the odd primer pierced which was interesting) but that was more to do with having the projectiles jammed in the lands more than the powder charge which was well within limits from memory (only 1 or 2 pierced out of the couple of hundred I reloaded but those particular ones were hard to close the bolt on from memory (20-30yrs ago so hard to recall exactly what was what) but pretty sure it was as I said from memory.

I still use the flattened primers as a guide or sticky bolt lift and cratering to some degree (the 204 has a habit of piecing primers if you don't use a harder offering - Rem 7.5 are harder than the CCI offerings so I use those and haven't had any issues so far with the load being over about a grain or so and have run it hotter but found the groups were better with what I run now).