fun with fire forming

[yorketransport]

I've got a thread about forming 338/375 Ruger brass from 8x68s case over on LRH which goes along with Jasent's thread about his 338/375 that he just finished and I though a couple folks here might think it was interesting too.

Here's the results from the forming I got done today. All cases were trimmed to 2.600" and formed using a false shoulder sized for a crush fit in the chamber. Everything was fired from a 338/375 Ruger Savage Striker.


Brass dimensions are an average of 10 samples of each brand. Norma and RWS case are capacities after a single fireform load.

Hornady 375 Ruger brass
Empty case weight: 262.2gr
H20 capactiy: 100.1

Norma 8x68s
Load: 22.8gr Trailboss, 277gr MTAC, CCI BR2
Empty case weight: 282.6gr
H20 capacity: 95.5
Length after forming: 2.585"


RWS 8x68s
Load: 21.8gr Trailboss, 307gr Hammer Hunter, CCI BR2
Empty case weight: 274.6gr
H20 capacity: 96.4gr
Length after forming 2.582"


I love the fact that I recovered a couple of the bullets in the dirt bank. Muzzle velocities are around 1900 fps and the bullets obviously didn't stabilize. The interesting part was that they grouped fairly well considering they're un-stable and the group was shot by my 16 year old daughter at 100 yards.

[jasnt]

Tagging along. Mynorma brass won’t be here till I’m headed to bear camp so it will be a few weeks before I can form

[luteai]

When I fireformed 30-06 AI brass I used bullseye with cornmeal to fill the case and a soap plug for a bullet. Would that work for your project? Cheap and could shoot in my garage no need to travel.

[jasnt]

Yes it would but you may not get a full fire form.  Plus if you have components you won’t use it’s a way to use those. Plus you still get to plink while fire forming

[yorketransport]

When I fireformed 30-06 AI brass I used bullseye with cornmeal to fill the case and a soap plug for a bullet. Would that work for your project? Cheap and could shoot in my garage no need to travel.

I’ve formed a lot of cases using the cream of wheat method over the years. It works pretty well but you have to clean the carbon and burnt cereal out of the barrel every 5-10 shots. There’s also some trial and error in finding the right powder charge that will give a good form without being over pressure and ruining the brass.

Using Trailboss and a bullet to form the cases takes all the guess work out of finding a load. All you do is either form a false shoulder to headspace off of or load the bullet long enough to jam into the rifling to hold the case hard against the bolt face. To figure out the powder charge all you do is fill the case with powder to the base of the bullet and weigh the charge. Trailboss burns very clean and is designed to generate pressure over a long curve compared to other powders. This makes it great for forming brass without the high pressures caused by using fast burning powders.

I always have a collection of odds and ends bullets that I can’t use for anything else, so this is a good use for them. The bullets I used for this project either shot poorly in all my guns (the 277 MTAC) or are samples of an early prototype design (the 307 Hammer Hunter). I may try using cast bullets too just to see how they work.

[jasnt]

Tracking says I’ll have my brass today

[yorketransport]

Tracking says I’ll have my brass today

Let the tedious forming process begin!!!!!

[jasnt]

Every time I order anything my mail man just leaves a pink slip. Won’t leave anything in my mail box.    gf will pick it up today

[jasnt]

Haven’t gotten around to forming yet but I do have few cases ready to form

[yorketransport]

I've had a chance to work with both the RWS and Norma 8x68s brass now and have 3 full power firings on each brand of brass. So far I can't tell a difference between the two. With a fully formed RWS case I use 78.3gr of H4350 with a 230gr ELD-x to get 2855 fps from the 18" barrel. With a Norma case I use 78.4gr H4350 to get 2850 fps with the same bullet. Between the two, I'd probably just go with the Norma brass since it's so cheap right now.

[jasnt]

I got 100 ct of Norma and 100 of Hornady.  Are you trimming before or after forming false shoulder?

[jasnt]

Got 25 cases about ready to fire form

[Crunchy]

I finally got 200 pieces of Norma brass.  Plan to fire form soon as rifle gets done.  Question for you though.  Do you run them through FL sizing die first, or just primer, powder and seat bullet?  My Norma brass neck seems tight enough to just seat a bullet without having to run through a die first.

[yorketransport]

As long as the necks look nice and round, I’d just load and shoot. You could run an expander through the necks to clean them up if they look a little rough.

[jasnt]

I neck up to 375 then down to 338 forming a false shoulder. In my chamber that will fit but I may need to trim it a bit.  Dosent look like the neck goes in the free bore to me.  Little more testing to be done before I decide

[Crunchy]

What kind of dies you using?  I have a cheapo 2 die set from RCBS that I am not in love with.  Almost impossible to fine tune bullet seating.  Need to step up my dies just not sure what to go with. 

[jasnt]

Rcbs fl die set for 338rcm and 375 ruger.   What cartridge you shooting?

[yorketransport]

I like Hornady dies whenever I can get them. They sell their micrometer adapter that you can screw onto any of their seating dies which can be a big improvement.

If you’re willing to spend a little more, CH4D makes great dies and has a lot of less common and wildcat dies on hand. The last sets I got from them were about $90 each for the 6.5 Badger and 375 BME.

[Crunchy]

Rcbs fl die set for 338rcm and 375 ruger.   What cartridge you shooting?

7mm Rem mag

[Crunchy]

Whats you take on Redding Type S Match Bushing Full Die Set 7mm Rem Mag.  Not to derail this thread.  Promise last question lol.

[jasnt]

Whats you take on Redding Type S Match Bushing Full Die Set 7mm Rem Mag.  Not to derail this thread.  Promise last question lol.

i use one for my 243 and I like it

[fly-by]

Got 25 cases about ready to fire form

I am going through this same process with a different cartridge using 300 WM brass and get a similar "donut" of shoulder brass that is now part of the neck, similar to your picture.  Do you neck turn at some point?  If so is it best to neck turn before or after fire forming?

[jasnt]

I do not but I would after fire forming

[yorketransport]

Got 25 cases about ready to fire form

I am going through this same process with a different cartridge using 300 WM brass and get a similar "donut" of shoulder brass that is now part of the neck, similar to your picture.  Do you neck turn at some point?  If so is it best to neck turn before or after fire forming?

Turn the necks after forming and after running an expander through the necks. I’d you have an expander like a K&M or the Sinclair style that uses a mandrel instead of a ball it works the brass less.

The idea behind this is that’s running the expander through the neck pushes the donut to the outside of the neck so it can be turned off.

[jasnt]

Started fire forming today.  Using 66gr re22 and 225gr sst cci250.   No trimming required but I may need to trim soon haven’t measured max case length.     Formed case was 2.630. Fireformed case is 2.605.
Left to right
375 ruger, 8x68s fire formed, ready to fire form 8x68s

[jasnt]

Got all my brass formed and loaded.  I’m curious how these fire forming rounds will shoot. For fun I’m going to chrono them and test the accuracy.

[jasnt]

Got 25 cases fireformed. Velocity was 2630 average.  Accuracy was great. All 25 rounds made a 1” hole.

[yorketransport]

Nice! Did you lose any cases while forming them?

[jasnt]

Not one yet. 

[jasnt]

Got 55 case fire formed now. Still no culls. Hoping to start load development today

[jasnt]

Final load is 78.2gr h4350 and cci250 a 250gr Berger at 3033 average with extreme spred of 11 FPS for five shots. 1/3 moa

[yorketransport]

I'm not impressed, you missed your aiming point.

[jasnt]

It’s tough when you use a bullet hole for a target.  Soon as I shoot one round idk which one was the target     Pretty impressed my self.  New stock is a huge improvement and so is the brass. Let’s hope it holds up as well after dozen firings

[jasnt]

Think I found a much better load today. Need to do some more shooting at distance

80gr of Re 22 and Berger 250gr .015” off  @3020 fps
81.5 had stiff bolt lift at slight primer crater @3075fps

[2MANY]

Had any issues with the CCI 250s lately??

[jasnt]

Had any issues with the CCI 250s lately??

no never had any issues with 250’s.  Buy them a couple cases at a time.

[jasnt]

Little more load work.

[b23]

Viht N570 could be a little to bulky or possibly to slow but Viht's new N565 powder may be one you should give a try.  N565 could possibly give you a free boost in velocity by just changing powders.

[jasnt]

Viht N570 could be a little to bulky or possibly to slow but Viht's new N565 powder may be one you should give a try.  N565 could possibly give you a free boost in velocity by just changing powders.

i may play with some of those powders as well.  It definitely seems to shoot better the faster it goes. 

[jasnt]

This Norma brass is nice!  Checking case capacity today and every single case was 98.8gr H2o.   (22/53 cases checked)