Wildcatters - another 30-338 question...

uncyboo · March 5, 2010, 12:46 PM

I am set now to start working on my 30-338. Starting with 338 Win brass, I understand you run it through the 30-338 die to simply neck it down. I got that part. The question is, for the initial case forming, do I full length size it and let the belt determine headspace, or leave a "donut" to get minimum or no headspace?

After the initial sizing I intend to trim, chamfer and deburr the mouths, uniform primer pockets and deburr/uniform flash holes. Or does the trimming need to happen after the first firing?

Loader9 · March 5, 2010, 05:52 PM

You need to run it thru the 30/338 die, then trim it and then make sure that the neck isn't too thick by chambering a blank round with bullet. Depending on who did the chamber, the neck might be too tight and neck turning required. Then fireform it and retrim again. I generally only have to trim every 3rd loading and I do it to keep the neck run close to the same. Usually it ends up being .002-.005 to trim. Once you have the brass fireformed, back the die up enough to use the shoulder for the headspace instead of the belt if you want the best accuracy. You can also use 300 H&H and 7mm Mag brass to make this cartridge but the 338 is preferable.

bgdv1 · March 5, 2010, 08:14 PM

+1 on what loader9 said, the only difference i have to do is i full lenth size mine each time. ive tried neck sizing and i have a tight chamber and have a hard time closing the bolt if i dont full length size. ive had this gun since i had it built in sept 1992.

GeauxTide · March 5, 2010, 09:34 PM

You can eliminate the thick neck worries by using 7mmRM cases, which would probably be less expensive. One more thing - I never full sized a 7mmRM or 7mmWBY case after the first firing. I could go to 7 full power loads until the primer pockets got loose.

uncyboo · March 5, 2010, 10:42 PM

Thanks guys. The reason I asked, was that I have about 30 once fired 338's and I also have 100 virgin 338's. I intended on using the once fired for initial load developement before I necked down 100 new pcs.

I sized one of the virgin cases just down to the neck/shoulder junction and it chambered no problem. When I did the same with the once fired, the bolt was pretty tight to close. Was just wondering it, for fire forming, was a zero headspace situation more desirable, or just let the belt determine headspace and neck size from there on. I took Loader9's advice and just FL resized it all. Thinking about getting the collet body die.

Seated a bullet and the neck thickness isn't a factor. No chamber marks on a smoked dummy round. This rifle does, however, seem to have a very long throat.

HiBC · March 6, 2010, 01:47 AM

All of the above info is good.
Often headspacing on a belt is a little loose.The original specs were maybe more about always chambering when some cape buffalo was fixing to stomp you,and less about reloading.If a slight donut serves to hold the brass tight to the bolt face for the first firing,thats a good thing.

Then the ideal is to have an RCBS precision mic,or a Stony point comparator,or some precise means to know ,for a bolt rifle,that you have moved the shoulder just enough to give you .002 head clearance.

For what it is worth,I have been very happy with a 200 gr Accu-Bond load.

uncyboo · March 6, 2010, 05:18 AM

Quote:

For what it is worth,I have been very happy with a 200 gr Accu-Bond load.

Am gonna go with those, or more likely the 190 SMK's...

Loader9 · March 6, 2010, 02:27 PM

If the rifle has a BR chamber, I'd suggest loading 62.0 grs IMR4350 under that 190 SMK. If it has the BR throat, it's probably real long. My OAL on the bench rifle is 3.495. The IMR loading is the correct node for that bullet at 2700'ps. Play around with the OAL to dial in best accuracy.

Bart B. · March 7, 2010, 09:20 AM

In wearing out three .30-.338 barrels shooting matches, I learned what everyone else who shot them well in competition did.

New cases made by full length sizing .338 Win. Mag. cases down to 30 caliber with about 5 thousandths headspace clearance shot the most accurate. Both the military teams and civilians winning matches and setting records tried conventional full length or neck only sizing and it never worked. The military teams just used new cases; they often gave their fired cases to civilians 'cause they never shot well reloaded. New case bodies had a ridge 1/32 inch in front of the belt after they was fired. That ridge caused interference with the chamber at that point when fired again; it wasn't swaged down by any case sizing die.

But a couple of folks found a way to reload fired belted cases getting rid of that ridge (or step) such that their performance equalled what new cases would do. It required fired cases to be resized back to virtual new case dimensions. To do so required a second body sizing die used to reduce body diameters all the way to the belt swaging that ridge back down to virtual new case dimensions, not 1/16th inch in front of it which normal full length sizing dies die. They took a regular full length sizing die then cut off its top just below the shoulder and cut its bottom off about 1/16th inch above the belt clearance counterbore. After depriming and cleaning the fired cases, they would first be sized in a standard full length sizing die setting the shoulder back about 3 thousandths. Then used the body die set to size the case all the way to the belt; the bottom of the body die barely touched the case belt when the ram was at the top of its stroke. This eliminated the interference between chamber and case at this point that regular full length sizing dies left.

If one doesn't do this, then any fired case sizing that makes the case head-to-shoulder dimension a fraction longer than the chamber so the bolt binds a bit when closed will force the case head hard against the bolt face. This lets that swelled part of the case right in front of the belt have minimum, but still some interference with the chamber. It gets worse as the firing pin drives the case head off the bolt face pushing the case a bit forward in the chamber. Accuracy will not be as good as with new cases or double-sized as explained above.

Larry Willis (www.larrywillis.com) now has a collet die that does the same thing. If one wants best accuracy with belted cases, using one of these dies is essential.

As far as the load's concerned, the popular load was 65 or 66 grains of IMR4350 under a Sierra 190 in standard SAAMI chamber dimensions for the .338 Win. Mag body and normal chamber neck diameters at .344 to .345 inch. Nobody got consistantly good accuracy with tight necks. Here's what my latest .30-.338 barrel did with new full length sized cases shooting 200-gr HPMK's and once fired double-sized cases shooting 190 HPMK's. 15 shots with each alternating between each load; all 30 shots fired in 20 minutes. Ten ring's 10 inches:

uncyboo · March 8, 2010, 11:35 AM

Quote:

If it has the BR throat, it's probably real long.

It does seem to have a very long throat. The only .308's I have on hand are Hornady 165 Interlock BTSP's, and seating one just barely enough to be strait won't touch the lands. It chambers without restriction.

Quote:

Larry Willis (www.larrywillis.com) now has a collet die that does the same thing. If one wants best accuracy with belted cases, using one of these dies is essential

All good info and much appreciated. Was gonna get one of these dies anyway. Maybe get it ordered today.

Thanks fellas....

March 5, 2010, 12:46 PM	#1
uncyboo Senior Member Join Date: November 7, 2008 Location: Shelby, MT Posts: 1,013	Wildcatters - another 30-338 question... I am set now to start working on my 30-338. Starting with 338 Win brass, I understand you run it through the 30-338 die to simply neck it down. I got that part. The question is, for the initial case forming, do I full length size it and let the belt determine headspace, or leave a "donut" to get minimum or no headspace? After the initial sizing I intend to trim, chamfer and deburr the mouths, uniform primer pockets and deburr/uniform flash holes. Or does the trimming need to happen after the first firing?

March 7, 2010, 09:20 AM	#9
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	In wearing out three .30-.338 barrels shooting matches, I learned what everyone else who shot them well in competition did. New cases made by full length sizing .338 Win. Mag. cases down to 30 caliber with about 5 thousandths headspace clearance shot the most accurate. Both the military teams and civilians winning matches and setting records tried conventional full length or neck only sizing and it never worked. The military teams just used new cases; they often gave their fired cases to civilians 'cause they never shot well reloaded. New case bodies had a ridge 1/32 inch in front of the belt after they was fired. That ridge caused interference with the chamber at that point when fired again; it wasn't swaged down by any case sizing die. But a couple of folks found a way to reload fired belted cases getting rid of that ridge (or step) such that their performance equalled what new cases would do. It required fired cases to be resized back to virtual new case dimensions. To do so required a second body sizing die used to reduce body diameters all the way to the belt swaging that ridge back down to virtual new case dimensions, not 1/16th inch in front of it which normal full length sizing dies die. They took a regular full length sizing die then cut off its top just below the shoulder and cut its bottom off about 1/16th inch above the belt clearance counterbore. After depriming and cleaning the fired cases, they would first be sized in a standard full length sizing die setting the shoulder back about 3 thousandths. Then used the body die set to size the case all the way to the belt; the bottom of the body die barely touched the case belt when the ram was at the top of its stroke. This eliminated the interference between chamber and case at this point that regular full length sizing dies left. If one doesn't do this, then any fired case sizing that makes the case head-to-shoulder dimension a fraction longer than the chamber so the bolt binds a bit when closed will force the case head hard against the bolt face. This lets that swelled part of the case right in front of the belt have minimum, but still some interference with the chamber. It gets worse as the firing pin drives the case head off the bolt face pushing the case a bit forward in the chamber. Accuracy will not be as good as with new cases or double-sized as explained above. Larry Willis (www.larrywillis.com) now has a collet die that does the same thing. If one wants best accuracy with belted cases, using one of these dies is essential. As far as the load's concerned, the popular load was 65 or 66 grains of IMR4350 under a Sierra 190 in standard SAAMI chamber dimensions for the .338 Win. Mag body and normal chamber neck diameters at .344 to .345 inch. Nobody got consistantly good accuracy with tight necks. Here's what my latest .30-.338 barrel did with new full length sized cases shooting 200-gr HPMK's and once fired double-sized cases shooting 190 HPMK's. 15 shots with each alternating between each load; all 30 shots fired in 20 minutes. Ten ring's 10 inches: Last edited by Bart B.; March 7, 2010 at 09:34 AM.

March 5, 2010, 05:52 PM	#2
Loader9 Senior Member Join Date: July 29, 2008 Posts: 949	You need to run it thru the 30/338 die, then trim it and then make sure that the neck isn't too thick by chambering a blank round with bullet. Depending on who did the chamber, the neck might be too tight and neck turning required. Then fireform it and retrim again. I generally only have to trim every 3rd loading and I do it to keep the neck run close to the same. Usually it ends up being .002-.005 to trim. Once you have the brass fireformed, back the die up enough to use the shoulder for the headspace instead of the belt if you want the best accuracy. You can also use 300 H&H and 7mm Mag brass to make this cartridge but the 338 is preferable.

March 5, 2010, 08:14 PM	#3
bgdv1 Senior Member Join Date: February 12, 2009 Location: butler,pa Posts: 146	+1 on what loader9 said, the only difference i have to do is i full lenth size mine each time. ive tried neck sizing and i have a tight chamber and have a hard time closing the bolt if i dont full length size. ive had this gun since i had it built in sept 1992.

March 5, 2010, 09:34 PM	#4
GeauxTide Senior Member Join Date: April 20, 2009 Location: Helena, AL Posts: 4,424	You can eliminate the thick neck worries by using 7mmRM cases, which would probably be less expensive. One more thing - I never full sized a 7mmRM or 7mmWBY case after the first firing. I could go to 7 full power loads until the primer pockets got loose.

March 5, 2010, 10:42 PM	#5
uncyboo Senior Member Join Date: November 7, 2008 Location: Shelby, MT Posts: 1,013	Thanks guys. The reason I asked, was that I have about 30 once fired 338's and I also have 100 virgin 338's. I intended on using the once fired for initial load developement before I necked down 100 new pcs. I sized one of the virgin cases just down to the neck/shoulder junction and it chambered no problem. When I did the same with the once fired, the bolt was pretty tight to close. Was just wondering it, for fire forming, was a zero headspace situation more desirable, or just let the belt determine headspace and neck size from there on. I took Loader9's advice and just FL resized it all. Thinking about getting the collet body die. Seated a bullet and the neck thickness isn't a factor. No chamber marks on a smoked dummy round. This rifle does, however, seem to have a very long throat.

March 6, 2010, 01:47 AM	#6
HiBC Senior Member Join Date: November 13, 2006 Posts: 8,286	All of the above info is good. Often headspacing on a belt is a little loose.The original specs were maybe more about always chambering when some cape buffalo was fixing to stomp you,and less about reloading.If a slight donut serves to hold the brass tight to the bolt face for the first firing,thats a good thing. Then the ideal is to have an RCBS precision mic,or a Stony point comparator,or some precise means to know ,for a bolt rifle,that you have moved the shoulder just enough to give you .002 head clearance. For what it is worth,I have been very happy with a 200 gr Accu-Bond load.

March 6, 2010, 02:27 PM	#8
Loader9 Senior Member Join Date: July 29, 2008 Posts: 949	If the rifle has a BR chamber, I'd suggest loading 62.0 grs IMR4350 under that 190 SMK. If it has the BR throat, it's probably real long. My OAL on the bench rifle is 3.495. The IMR loading is the correct node for that bullet at 2700'ps. Play around with the OAL to dial in best accuracy.