Fireforming 7 STW brass from 300 H&H

[eshorebwhntr]

I have had problems with gas blowing by the primer on my STW with Remington brass starting about the 3rd to 4th reload. With some research on this forum and others I learned that you can fireform STW brass from 300 H&H. I couldn't find any STW brass anywhere so I figured what the hell, I'll give it a shot.

Started with standard H&H cartridges from Norma.

Step 1 - Anneal the necks. Standard torch. Turned the lights out in the room. Heated them evenly using a power drill to spin them about 5-7 seconds until I could see a slight glow from the necks with no lights on in the room.

Step 2 - Resize the necks down from 30 cal to 7mm.

Step 3 - Prime the case with a small rifle primer. I didn't have any of these and F210 was all I could find so that is what I used this time.

Step 4 - Fill case to the top with Red Dot powder. Pour it out on a scale and weigh it. Came to 42.6 gr. Took 5% of that which turned out to be 2.13gr. Seemed a little low to me and I was being safe anyway so I rounded up to 2.5 gr to start with.

Step 5 - Loaded the first prepped case with 2.5gr Red Dot. Filled the rest of the case with Cream of Wheat. Capped the case with soap plugged in the end to prevent spilling.

Step 6 - Fired the cartidge.

This didn't provide the desired results. It blew the shoulder area out OK but the full body was still incomplete.

So I repeated the steps above increasing the load charge to 4.5gr and then 6.0gr of Red Dot. 4.5gr did the job pretty well but 6.0 made the case body just a little more concentric and filled out so I went with that for the rest of the cases. No pressure problems at all in my gun with 6.0 grains of Red Dot.

After that I loaded up a 180 over 78.8 gr of H-1000 and fired it to complete the comparison. From left to right in the picture in case you can't read the sharpie writing is a new case from Remington in STW, new Norma 300 H&H, annealed 300 H&H, 2.5gr Red Dot fireformed, 4.5gr Red Dot fireformed, 6.0gr Red Dot fireformed, 78.8gr H-1000 shot through fireformed case w/ 6.0gr Red Dot, and a 4x fired Remington case from my old recipe with the 180 VLD.

All in all I think it went well. I'm going to load a few more rounds this weekend and begin working up a load again. I use to shoot the VLD's but I'm going to try the Hybrid's and see how they do on targets and animals. I do think this brass will yield much longer life in the primer pocket area. There is a decernible difference in the pressure required to put the primers in these cases as compared to Remington. No suprise to most I guess.

I know I didn't do anything ground breaking here that is worthy of acclaim. Just thought I'd share my info for any other novices like myself that might find it useful.

 

[Lefty7mmstw]

I do the 375's in fewer steps than that, but I abhor make work and avoid it like the plague. With the 300 h@h I'd simply neck down and fireform with a load that's a full 10% or more down from top end. Keep it mild and it won't beat the barrel up.

In any case good looking brass and with a bit of care it'll last as long as the factory stamped stuff.

P.S. ... I've shot thousands of stw's and haven't lost a primer pocket in over ten years. I went to as slow of a powder as I could get in the dang thing and got the velocity without as high of a peak pressure.

 

[7stw]

I have had problems with gas blowing by the primer on my STW with Remington brass starting about the 3rd to 4th reload. With some research on this forum and others I learned that you can fireform STW brass from 300 H&H. I couldn't find any STW brass anywhere so I figured what the hell, I'll give it a shot.

Started with standard H&H cartridges from Norma.

Step 1 - Anneal the necks. Standard torch. Turned the lights out in the room. Heated them evenly using a power drill to spin them about 5-7 seconds until I could see a slight glow from the necks with no lights on in the room.

Step 2 - Resize the necks down from 30 cal to 7mm.

Step 3 - Prime the case with a small rifle primer. I didn't have any of these and F210 was all I could find so that is what I used this time.

Step 4 - Fill case to the top with Red Dot powder. Pour it out on a scale and weigh it. Came to 42.6 gr. Took 5% of that which turned out to be 2.13gr. Seemed a little low to me and I was being safe anyway so I rounded up to 2.5 gr to start with.

Step 5 - Loaded the first prepped case with 2.5gr Red Dot. Filled the rest of the case with Cream of Wheat. Capped the case with soap plugged in the end to prevent spilling.

Step 6 - Fired the cartidge.

This didn't provide the desired results. It blew the shoulder area out OK but the full body was still incomplete.

So I repeated the steps above increasing the load charge to 4.5gr and then 6.0gr of Red Dot. 4.5gr did the job pretty well but 6.0 made the case body just a little more concentric and filled out so I went with that for the rest of the cases. No pressure problems at all in my gun with 6.0 grains of Red Dot.

After that I loaded up a 180 over 78.8 gr of H-1000 and fired it to complete the comparison. From left to right in the picture in case you can't read the sharpie writing is a new case from Remington in STW, new Norma 300 H&H, annealed 300 H&H, 2.5gr Red Dot fireformed, 4.5gr Red Dot fireformed, 6.0gr Red Dot fireformed, 78.8gr H-1000 shot through fireformed case w/ 6.0gr Red Dot, and a 4x fired Remington case from my old recipe with the 180 VLD.

All in all I think it went well. I'm going to load a few more rounds this weekend and begin working up a load again. I use to shoot the VLD's but I'm going to try the Hybrid's and see how they do on targets and animals. I do think this brass will yield much longer life in the primer pocket area. There is a decernible difference in the pressure required to put the primers in these cases as compared to Remington. No suprise to most I guess.

I know I didn't do anything ground breaking here that is worthy of acclaim. Just thought I'd share my info for any other novices like myself that might find it useful.

Good job man, and I know it took a lot of effort, and it is a learning experience in the long run. Two very important things are going to come out of it. You now have brass, which in our present climate, is a very good thing, but more importantly, you have the BEST brass you could ever have, in this caliber, or most any other caliber for that matter.
I think someone told me that they used like 30 grains of H380, cream of wheat, and a soap plug, and the result was near perfect.
In any event you are on the right path, and maybe it may require two firings, using the higher end charge the you used with the red dot. Good job there Eastern Shore Bird!!

 

[eshorebwhntr]

I thought of just running a straight load in this round and not fooling with the fire forming but I didn't based on what a friend of mine told me. He has a 30 Hart which is a wildcat based off of the 300 weatherby. His accuracy suffered substantially when running 300 weatherby brass through that chamber and then had to rework another load once all the brass was formed to 30 Hart. I already basically have a load that works and a 300 HH will not hold that much powder. The new fire formed cases will. Jury is still out on if they will be as accurate as the load was in new factory R-P cases.

Also, I was probably getting loose pockets on the 4x firing because of my bullet/seating depth. I was running 180 berger VLD's .006 into the lands. I've now switched to 180 Hybrids which by everyones testimony so far shoot just as good .010 jammed as they do .060 jump. Again, I'll have to see for myself.

Just wanted to clear up, I don't do all the steps I showed pics for (ie 2.5, then 4.5, then 6.0). I anneal, size, charge to 6.0gr, fill, and shoot. I just wanted to show everyone what I went through and why I decided on my recipe so they could feel safe if they wanted to attempt it.

Hope to post some accuracy/velo results soon when I get time to load the brass I've made and get to the range with em.

 

[Lefty7mmstw]

I thought of just running a straight load in this round and not fooling with the fire forming but I didn't based on what a friend of mine told me. He has a 30 Hart which is a wildcat based off of the 300 weatherby. His accuracy suffered substantially when running 300 weatherby brass through that chamber and then had to rework another load once all the brass was formed to 30 Hart. I already basically have a load that works and a 300 HH will not hold that much powder. The new fire formed cases will. Jury is still out on if they will be as accurate as the load was in new factory R-P cases.

Also, I was probably getting loose pockets on the 4x firing because of my bullet/seating depth. I was running 180 berger VLD's .006 into the lands. I've now switched to 180 Hybrids which by everyones testimony so far shoot just as good .010 jammed as they do .060 jump. Again, I'll have to see for myself.

Just wanted to clear up, I don't do all the steps I showed pics for (ie 2.5, then 4.5, then 6.0). I anneal, size, charge to 6.0gr, fill, and shoot. I just wanted to show everyone what I went through and why I decided on my recipe so they could feel safe if they wanted to attempt it.

Hope to post some accuracy/velo results soon when I get time to load the brass I've made and get to the range with em.

The brass will be as good or better than the correct headstamp stuff. I've done the fireforming with pistol powder and farina and I've shot live ammo; I've gone to the latter as the pistol powder and cereal makes a mess of the barrel. Of course I did do nearly 100 rounds brass in around an hour.
My old 7stw liked a mild load of h4831 with a 120 sierra for fireforming; it shot cloverleafs fireforming. My dad's stw hated that load and shot groups in the inches. You never know where you'll land until you try it.
I'm glad you have changed your load to ease up on the primer pockets; working a rifle hard isn't any good for its longevity.

 

[Kevin Thomas]

Hmmmm . . . this sounds vaguely familiar.

 

[J E Custom]

When I built my 7 STW there was no commercial ammo available and we had to make it from 8 mm REM brass. A Square later came out with ammo that made it a little easier. There loaded ammo was 3500 ft/sec with 140 grain bullets. (Later they backed of to 3450 ft/sec).

When I could get it I used the 8mm Rem brass to make my 7 STW cases. A Square loaded some in there brass that was very tough and I still have some of it also.

Ether case has held up very good and the 8mm Rem just needs the neck to be sized.

I never loaded any Squibb loads to fire form because of the potential problems and just loaded down 3 or 4 grains to get good sharp shoulders.

I also loaded some loads very hard (140 grain @ 3790 in a 31" barrel) and brass life suffered. after 3700 ft/sec the accuracy went away, so I backed of to 3600 ft/sec and brass life was ok (4 to 5 shots) before the primer pockets felt a little loose.

I also found that the 375 H&H brass worked very well and I was able to turn the necks just enough to true them without thinning the necks.

The STW brass can be made from many other cartridges, These are just the ones that I used.

I Hope this gives all the 7 STW shooters other sources of brass.

J E CUSTOM

 

[lloydsmale]

im with him. 8mm mag brass just needs to be necked down and go. Its usually easier for me to find 8mag brass for my 8mag then 300 H&H brass for my H&H

When I built my 7 STW there was no commercial ammo available and we had to make it from 8 mm REM brass. A Square later came out with ammo that made it a little easier. There loaded ammo was 3500 ft/sec with 140 grain bullets. (Later they backed of to 3450 ft/sec).

When I could get it I used the 8mm Rem brass to make my 7 STW cases. A Square loaded some in there brass that was very tough and I still have some of it also.

Ether case has held up very good and the 8mm Rem just needs the neck to be sized.

I never loaded any Squibb loads to fire form because of the potential problems and just loaded down 3 or 4 grains to get good sharp shoulders.

I also loaded some loads very hard (140 grain @ 3790 in a 31" barrel) and brass life suffered. after 3700 ft/sec the accuracy went away, so I backed of to 3600 ft/sec and brass life was ok (4 to 5 shots) before the primer pockets felt a little loose.

I also found that the 375 H&H brass worked very well and I was able to turn the necks just enough to true them without thinning the necks.

The STW brass can be made from many other cartridges, These are just the ones that I used.

I Hope this gives all the 7 STW shooters other sources of brass.

J E CUSTOM