Modifying a case for hornady overall length gauge

Reloading equipment, methods, load data, powder and projectile information.

Modifying a case for hornady overall length gauge

Post by Kelsey Cooter » 30 Jan 2018, 7:49 pm

Whos modified their own case for the hornady oal gauge? Why does the case need to be full length sized? I dont have a neck expander die, and buying one would cost more then just buying a modified case from hornady. So im wondering why cant i just modify a case without full length sizing? Or is there a good way to expand the neck without using a expander die?
Kelsey Cooter
Corporal
Corporal
 
Posts: 408
Queensland

Re: Modifying a case for hornady overall length gauge

Post by marksman » 31 Jan 2018, 7:20 am

the case should be a good fit to your chamber, fireformed to get a true reading
I don't use this method but know BRT can modify your fireformed cases cheap for you
http://brtshooterssupply.com.au/index.html
“If you do not read the newspapers you are uninformed. If you do read the newspapers you are misinformed”. Mark Twain
User avatar
marksman
Colonel
Colonel
 
Posts: 3660
Victoria

Re: Modifying a case for hornady overall length gauge

Post by Apollo » 31 Jan 2018, 8:06 am

You don't need to full length size a case, it needs to be a case that is fired in the chamber for which the case is to be used if it's for precision measurements. You can use a Hornady case or another but if you want exact measurements you will need to know what the difference in length is compared to your own chamber and make that adjustment when seating bullets.

If it's not for precision target use where you need to be accurate down to 0.001" then anything else would probably be fine. You do need to make sure a bullet will slip down the case neck without any resistance.

I used to make a lot myself for people until I lost the use of a small lathe to do the job.
Apollo
Warrant Officer C1
Warrant Officer C1
 
Posts: 1327
New South Wales

Re: Modifying a case for hornady overall length gauge

Post by Kelsey Cooter » 31 Jan 2018, 7:54 pm

Ok sounds good thanks fellas
Kelsey Cooter
Corporal
Corporal
 
Posts: 408
Queensland

Re: Modifying a case for hornady overall length gauge

Post by sungazer » 01 Feb 2018, 7:56 am

I am thinking of making one of these does anyone have a few good pictures and tips for making on. Apollo anything you could pass on would be very appreciated. I have a small lathe and drill and taping or threading is no problem at least on the second try :D
sungazer
Sergeant Major
Sergeant Major
 
Posts: 1525
Other

Re: Modifying a case for hornady overall length gauge

Post by brett1868 » 01 Feb 2018, 8:14 am

I make the cases for myself and have the appropriate tap for the Hornady tool. The thing to note is you also need the comparator to measure the gauge. Also each different batch / type and brand of projectile needs to be run through the process of establishing the max OAL. If you don’t want the hassle you’re more then welcome to Send me 2 fire formed cases and I’ll drill / tap them for you. PM me for details if you like.
How's my posting?
Complaints, Concerns - 13 11 14
User avatar
brett1868
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 3017
New South Wales

Re: Modifying a case for hornady overall length gauge

Post by Apollo » 01 Feb 2018, 9:39 am

sungazer wrote:I am thinking of making one of these does anyone have a few good pictures and tips for making on. Apollo anything you could pass on would be very appreciated. I have a small lathe and drill and taping or threading is no problem at least on the second try :D


The Tap you need is a 5/16-36 Tpi HSS available from a lot of places. Mine came from HSS a long time ago.

http://www.hss.net.au/product_info.php? ... cts_id=643

If you can wait they are about 1/3 the price on eBay from China. The correct drill is a 9/32" HSS but you can use one slightly bigger like 7.20mm. I have used one up to 7.5mm when I was trying to cut the thread in a cheap drill press but it wasn't near as tight a final fit.

In the small lathe I used a 3 Jaw Chuck and gripped the case head at the strongest point at the case head level with the chuck jaws so as to not put any pressure on the actual case body. Just tight enough not to slip when drilling. That was the only time the lathe was powered up. Swap the drill out of the headstock for the Tap and cut the thread by hand, slow feed and clear the cut numerous times until it is threaded all the way. Then swap the Tap out for a large drill or countersink and clear the Burr created on the case head so it is flat. Lube the Tap.

Before any of this for the Cases I wanted to use, typically two cases just in case. I FLS the cases then fired them in the Chamber twice to make sure they were fully fire formed. Check the case neck with a bullet to make sure a bullet slides down the neck into the case without any resistance at all. If not and some I have had were too tight for the bullet to fall into I would then neck turn some material off the outside of the neck and fire again. You could also ream the inside of the neck if you have the equipment needed. I then used a Primer Punch to remove the spent primer before drilling.

Other than the first FLS I do not touch the case again with a standard Sizing Die. You do not want to change the case in any way after fire forming.

I use a Sinclair Comparator Nut &/or Sinclair Comparator Inserts and Mitutoyo Calipres for taking measurements several times or more, especially if I'm seating bullets on the lands or a couple of thou off the lands.

I have a Modified Case or two for every Rifle/Chamber I own as well as a couple of friends chambers.

Hope I covered most things, it's been some time since I needed to make a Modified Case.
Apollo
Warrant Officer C1
Warrant Officer C1
 
Posts: 1327
New South Wales

Re: Modifying a case for hornady overall length gauge

Post by sungazer » 01 Feb 2018, 11:17 am

Thanks guys I sort of get what is needed. Brett I understand about doing it for every bullet and I am trying a few and want to get the measurement better than I have been doing before. I used a club members last week but didn't take a photo and didn't get to see how he used it. I was planing on making the whole thing myself so it doesn't really matter what thread size I use does it? Just make sure the thread is the same on the case as the rod. But thanks for the size. I bought a tap from someone in Broadford for making a muzzle break they seem like good guys Im not far from them and was thinking of going and seeing them as I want to get a few bits for the lathe.

The bit I dont get yet is how the case was pushed in and supported. I will google pictures will come up and then I will get it.
sungazer
Sergeant Major
Sergeant Major
 
Posts: 1525
Other

Re: Modifying a case for hornady overall length gauge

Post by Apollo » 01 Feb 2018, 7:12 pm

Apollo
Warrant Officer C1
Warrant Officer C1
 
Posts: 1327
New South Wales

Re: Modifying a case for hornady overall length gauge

Post by sungazer » 01 Feb 2018, 7:37 pm

yep thanks I googled them as well and now see how they are made. I initially thought the rod was an all thread and you turned that in the case pushing the bullet out. I now see you just use a plain slide to push it out and then can clamp it with screw on the tube and it is the tube that is screwed into the base of the case. All good should be able to find some parts to make one.
sungazer
Sergeant Major
Sergeant Major
 
Posts: 1525
Other

Re: Modifying a case for hornady overall length gauge

Post by Apollo » 01 Feb 2018, 7:41 pm

If you want some Photos and/or Measurements send me a PM with your Email Address and I'll send you some if you wish.
Apollo
Warrant Officer C1
Warrant Officer C1
 
Posts: 1327
New South Wales


Back to top
 
Return to Reloading ammunition