280 AI : Any Down Side To Fire Forming With All Copper Bullets?

[PA Plumber]

Got to the range today.
X-bolt barrel break in and brass fire forming.
50 grain and 51 grains were the two H4350 charges used.
I couldn't bring myself to jam the bullet into the lands, so it's seated at or just under touching.
1st pic is of the shells using the two different powder charges. I can't tell a difference.
2nd pic is still barrel break in. 4 shot group at 100 yards. 2 shots, clean, 2 shots.

 

[WildRose]

Got to the range today.
X-bolt barrel break in and brass fire forming.
50 grain and 51 grains were the two H4350 charges used.
I couldn't bring myself to jam the bullet into the lands, so it's seated at or just under touching.
1st pic is of the shells using the two different powder charges. I can't tell a difference.
2nd pic is still barrel break in. 4 shot group at 100 yards. 2 shots, clean, 2 shots.

View attachment 348360

View attachment 348361

Is that a 26 Nos necked down to six with the shoulder pushed forward?

 

[RidgeTop]

Why not form with corn meal? Use some pistol powder, put in the corn meal and cover with some cotton. I have used Unique because I have it.

 

[PA Plumber]

Is that a 26 Nos necked down to six with the shoulder pushed forward?

280 Rem to 280 AI

 

[PA Plumber]

Why not form with corn meal? Use some pistol powder, put in the corn meal and cover with some cotton. I have used Unique because I have it.

I thought about this a lot. I do have a few different pistol powders around.

I have to break in the barrel anyway, figured I might as well shoot it, form the brass and zero in the new scope.
I am enjoying shooting the new gun and after 50 -60 rounds, should be sorta comfortable with it.

 

[PA Plumber]

Last four shots fire forming the Federal Brass. Stopped at 59 because one neck got scrunched from the new seating die that wasn't cut right from RCBS.

Went from just under 1 1/2" group to less than 1 1/8". Bullets were seated at the lands.

 

[PA Plumber]

The GMX bullets did fine for fire forming. Don't know if a cup and core bullet would have led to less copper wash. Likely would have on this new barrel, but it seems to be settling down.

Bullet seating depths set from touching the lands to .020 off. Had a 7 shot group that was just a touch over 1 1/2" but I was shooting quickly because a fellow beside me had a 300 Win Mag with a brake, and it was loud! Last 4 shots, pictured above, I was by myself at the range.

 

[Hugnot]

Bullets & powder are expensive. Fireform with cream of wheat (COW) method. Use starting loads of 10% case capacity of mid range burning rate pistol powder, like case capacity 70 grains try a starting load of 7 grains of pistol powder & work up. It will take approximately 20,000 psi to fire form a case, so nice sharp well defined shoulders are formed. Be sure to get a good crush fit. Any kind of primer will work like large pistol for large rifle primed cases. Fireforming loads with bullets will never equal ballistic performance of the final product. Not going to spend $40-$50 for a box of bullets used for fire forming. An exception might be firforming (FF) .223 AI brass using cheapy bullets at under $0.15 each & with minor gain in case capcity. Barrel life is another consideration. Taking a primed case (1) charge powder, (2) wad toilet paper, (3) COW to base neck, (4) wad toilet paper. Sweep out chamber after each shot; I use bronze brush with paper towel wrap. Be sure all junk is removed from case before loading.

Some skip the COW & TP and just charge with pistol powder & point barrel straight up. (Boom, but not shooting at birds)

Be careful - pistol powder is real frisky & can generate enough pressure to destroy stuff.

I FF as part of process to make 6mm AI from 6mm Rem, 7X57 & .280 cases from .270 Win.

 

[PA Plumber]

Bullets & powder are expensive. Fireform with cream of wheat (COW) method. Use starting loads of 10% case capacity of mid range burning rate pistol powder, like case capacity 70 grains try a starting load of 7 grains of pistol powder & work up. It will take approximately 20,000 psi to fire form a case, so nice sharp well defined shoulders are formed. Be sure to get a good crush fit. Any kind of primer will work like large pistol for large rifle primed cases. Fireforming loads with bullets will never equal ballistic performance of the final product. Not going to spend $40-$50 for a box of bullets used for fire forming. An exception might be firforming (FF) .223 AI brass using cheapy bullets at under $0.15 each & with minor gain in case capcity. Barrel life is another consideration. Taking a primed case (1) charge powder, (2) wad toilet paper, (3) COW to base neck, (4) wad toilet paper. Sweep out chamber after each shot; I use bronze brush with paper towel wrap. Be sure all junk is removed from case before loading.

Some skip the COW & TP and just charge with pistol powder & point barrel straight up. (Boom, but not shooting at birds)

Be careful - pistol powder is real frisky & can generate enough pressure to destroy stuff.

I FF as part of process to make 6mm AI from 6mm Rem, 7X57 & .280 cases from .270 Win.

Appreciate the post.
These first cases were part of barrel break-in and scope sight in. (although the scope only took one shot)
I didn't mind one bit using fuel and copper to do this the first time.
Any more cases and I'll likely use the COW method. I have oodles of pistol powders and 100 Large pistol Magnum primers and no large pistol. A buddy gave me the pistol primers years ago and I forgot I had them. Good way to burn them up.

 

[PA Plumber]

I guess I could mention...
With 50 grains of H4350, 139 gr GMX bullets seated just touching the lands, I was getting 2750 fps. Extremely pleasant to shoot.
As far as I can tell, formed brass looks decent.

 

[Mark37082]

You could alway practice with COW load on carpenter bees. I hate carpenter bees. . Good luck and let us know how it goes.

 

[PA Plumber]

Getting ready to start putting together hunting loads, and I've noticed a tiny mark in the area of the new shoulder. Almost looks like an incipient head separation line. It's about 3/16" down from the bottom of the new shoulder.

Cut the brass in half, took off the bur, and it's measuring at .014 at the line. Case mouth is also measuring .014.
There has to be a little stress seam there, but I can't see it.

 

[PA Plumber]

 

[Azrael]

Why not use the COW method and no bullets?