30-338 Freebore

[jehan12413]

Hello all,
I haven't been on these forums for a while, so I figured I would post a couple questions regarding some issues I've been having. I have a Remmington 700 chambered for 30–338 24" barrel 1-12 twist. Prior to having this gun built most of my shooting was with a Remington 700 chambered for 300 Weatherby magnum. Due to the amount of free bore I never had any issues regarding bullet, seating depth, or chamber pressure. But the 3-338 seems to be an entirely different animal and is much more finicky. First of all, I have tried Remmington, Norma, and Hornady brass, all of which have the shoulder set too far back. In order to prevent head separation during the first firing I have to use 190 grain bullets seated, touching the lands. This results in a bullet to neck engagement of only .100" but it does solve the problem and allows the shoulders to form during that first firing. There are no issues with future firings as I have my die adjusted to not setback the shoulder. Unfortunately, this limits me to 190 grain bullets for that first firing. 168s are too short and I have not tried 175s yet. So my question is once my brass has been fire formed. How deep should I seat the bullets for future firings? I have read numerous articles and opinions varying from touching the lands to .050 off. Many seem to recommend .020 off. So I figured I would just throw the question out there and see what people think. Thanks in advance for the advice.
John

 

[WeiserBucks]

You'll have to experiment and see what it likes.

 

[MagnumManiac]

You'll have to determine actual land length on touching first.
To do this, cut 2 .040" slits opposite each other in the case neck, clean off the burrs, size the neck, seat the bullet you want to use long, and carefully chamber it. Open and close the bolt handle a few times, this helps to not stick the bullet in rifling, then carefully extract the case being careful not to let it bang the action with the plunger ejector pushing the case across.
I do this with a disassembled bolt, no firing pin attached, you can leave the ejector in place, just hold the case while extracting it.
Measure this several times, when you get a few agreeing measurements, then that is correct.
Working SHORTER from this number increases clearance to rifling.
Just a word about seating depth, numbers quoted on the interwebs are BS and have no correlation to accuracy. .020", .010" or .030" off is neither here nor there until it is tested in YOUR RIFLE.

Cheers.

 

[FEENIX]

Hello all,
I haven't been on these forums for a while, so I figured I would post a couple questions regarding some issues I've been having. I have a Remmington 700 chambered for 30–338 24" barrel 1-12 twist. Prior to having this gun built most of my shooting was with a Remington 700 chambered for 300 Weatherby magnum. Due to the amount of free bore I never had any issues regarding bullet, seating depth, or chamber pressure. But the 3-338 seems to be an entirely different animal and is much more finicky. First of all, I have tried Remmington, Norma, and Hornady brass, all of which have the shoulder set too far back. In order to prevent head separation during the first firing I have to use 190 grain bullets seated, touching the lands. This results in a bullet to neck engagement of only .100" but it does solve the problem and allows the shoulders to form during that first firing. There are no issues with future firings as I have my die adjusted to not setback the shoulder. Unfortunately, this limits me to 190 grain bullets for that first firing. 168s are too short and I have not tried 175s yet. So my question is once my brass has been fire formed. How deep should I seat the bullets for future firings? I have read numerous articles and opinions varying from touching the lands to .050 off. Many seem to recommend .020 off. So I figured I would just throw the question out there and see what people think. Thanks in advance for the advice.
John

John,

As with anything else, YMMV. I, too, ideally .015 - .020" off the lands; however, as @WeiserBucks noted, you need to find what your rifle actually likes. I have three .300 WMs, and one of them is loaded with Berger 190 VLDs (1:11" or faster) at .080" off the lands. I am not sure which 190 you are loading, but the Berger has a recommendation to make the Berger 190 VLD bullets.com/vld-making-shoot/, up to .120-130" off the lands. Too bad, yours is 1:12" and not 1:10" or faster; otherwise you would have plenty of bullet choices, if you want to chase/load the lands. Good luck!

 

[AZShooter]

I had a 30-338 around 30 yr ago. Great round!

Regarding your issue having to use the 190s for fireforming. You could make a false shoulder instead of engaging the lands.

As for what jump works: Often the magazine limits OAL. I like to seat the bullet out as far as possible then check for proper feeding. If that works, then check to see if the bullet is not engaging the lands. A simple test is to polish the bullet with fine steel wool and carefully place a dummy round into chamber close bolt and carefully remove to minimize any marks on the bullet. If it is into the lands, it is easy to see the evenly spaced indentations on the bullet.

While not everyone likes Berger bullets, the hybrid bullets are not finicky with seating depth.
I have found all that is necessary is to seat to fit and feed and work up a load. Have never had to alter the seating depth to get a rifle to shoot.

Rifles loaded with Berger hybrids to date:

Two 6BRs 105 hybrid target

Three 6-284 95 gr classic hunter hybrid and 105 hybrid target

7-08 168 classic hunter hybrid

284 win 168 classic hunter hybrid and 180 match target hybrid

Four 7 Rem mags 168 classic hunter hybrid

7 mag 180 hybrid target

308 Win 168 classic hunter and 215 hybrid target

Two 300 WSMs 180 elite hunter and 230 gr target hybrid

Two 300 Win mags 215 gr target hybrid

Four 300 RUMs 230 gr target hybrid

Two 338 RCMs 300 gr hybrid OTM tactical

Two 338 RUMS with 300 gr hybrid OTM tactical

 

[jehan12413]

John,

As with anything else, YMMV. I, too, ideally .015 - .020" off the lands; however, as @WeiserBucks noted, you need to find what your rifle actually likes. I have three .300 WMs, and one of them is loaded with Berger 190 VLDs (1:11" or faster) at .080" off the lands. I am not sure which 190 you are loading, but the Berger has a recommendation to make the Berger 190 VLD bullets.com/vld-making-shoot/, up to .120-130" off the lands. Too bad, yours is 1:12" and not 1:10" or faster; otherwise you would have plenty of bullet choices, if you want to chase/load the lands. Good luck!

I am using sierra 190 MK for fire forming as I still have many boxes of them. And yes I will have to see what it likes, I was hoping to not have to be that close to the lands as I would like more bullet seating depth. This will be more of a concern if I decide to shoot lighter bullets. As I mentioned my previous experience was with the 300 WBY and if I recall correctly that had .375" freebore which meant certain bullets would be completely out of the cartridge before contacting the lands. I never had any accuracy problems with that one although it was for hunting not competition.
Thanks again

 

[jehan12413]

You'll have to determine actual land length on touching first.
To do this, cut 2 .040" slits opposite each other in the case neck, clean off the burrs, size the neck, seat the bullet you want to use long, and carefully chamber it. Open and close the bolt handle a few times, this helps to not stick the bullet in rifling, then carefully extract the case being careful not to let it bang the action with the plunger ejector pushing the case across.
I do this with a disassembled bolt, no firing pin attached, you can leave the ejector in place, just hold the case while extracting it.
Measure this several times, when you get a few agreeing measurements, then that is correct.
Working SHORTER from this number increases clearance to rifling.
Just a word about seating depth, numbers quoted on the interwebs are BS and have no correlation to accuracy. .020", .010" or .030" off is neither here nor there until it is tested in YOUR RIFLE.

Cheers.

I wish I had thought about doing it that way ( I did it by using a black marker on some dummy rounds and chambering with firing pin removed)

 

[FEENIX]

I am using sierra 190 MK for fire forming as I still have many boxes of them. And yes I will have to see what it likes, I was hoping to not have to be that close to the lands as I would like more bullet seating depth. This will be more of a concern if I decide to shoot lighter bullets. As I mentioned my previous experience was with the 300 WBY and if I recall correctly that had .375" freebore which meant certain bullets would be completely out of the cartridge before contacting the lands. I never had any accuracy problems with that one although it was for hunting not competition.
Thanks again

Except for the cartridges, WBYs were designed for long freebore. My .257 WBY is .378" IIRC. However, I do not have a problem shooting factory 100 SPs and can load 131s to 163s touching the lands. The 190 SMKs are excellent bullets, if you can stabilize them with 1:12".

 

[Monster Toms]

What case are you starting with? I've been shooting a 30-338 for 23 years always started with 7mm Mag necked up, loaded and started shooting. fire form accuracy has always been just as good as the 4th or 5th reloading. I have shot both Remington and Winchester brass with equal results. Started with 165 ballistic tips but for the last 10 years 180 accu-bonds.

 

[jehan12413]

I am starting with 338 WIN MAG and necking down. So as AZShooter suggested I could create a false shoulder for the first firing rather than loading long. I started with REM brass which was ok but prefer Hornady. Norma is by far the best with the shoulders not set back as far and requires very little if any neck trimming.

 

[MagnumManiac]

I ran a 308 Norma Magnum for a good while, when brass was difficult to get, I just ran 338WM through my die and fire formed. It had close shoulder expansion, only .010" on WM brass. My throat measured .220", which was standard for that round.
I liked the round, the 300WM and 300 Weatherby were both faster and easier to get brass for at the time.
You really don't need to worry about throat length, there is always a measurement that works, whether it's long or short.

Cheers.