Is This Common with a rebarrel?

Stats Shooter · March 10, 2017, 04:41 PM

So I built my savage 110 .300 wm into a target rifle. It is in a Chassis stock and takes magazines.

I put a Shilen #8 28" barrel on it. I headspaced it using the barrel nut and Foster's gauges. It will close easy on the go gauge and about half way on the no go.... I'm pretty sure that's about perfect. I torqued the barrel nut to 70 ft lbs.

Now, the new chamber will barely accept my older brass from my previous rifle. I FL size it using RCBS dies and she'll holder, sizing it down until it touches the shell holder. I do not cam-over.

The new chamber easily accepts new factory ammo, I bought a box of "cheap" Winchester 150 gr ammo and fired all 20. No problems at all. The fired shells will easily rechamber that were fired in the new chamber. My chamber gauge says that they all grow to 2.2715 exactly from, (with respect to the win factory ammo average) 2.2560.... Which means the shoulder grew out .0155.

After 20 firings, the old sized brass will chamber, but I have to tap the bolt with a rubber mallet to get it back out. I noticed some scratches on the old, hard to extract, brass after extraction, but the shoulder diameter is ten thousandths smaller than the new fireformed brass. I have measured from case head to datum but I'm afraid measurement error is too high for me to extract meaningful information.

It isn't a huge deal, I'm going to need brass anyway, but I was going to use the old brass to do jump/jam development so that I didn't have to work the new stuff.

AllenJ · March 10, 2017, 05:15 PM

My experience with belted magnum cases is that after 4 or 5 firings they'll need to be put through a collet die to resize the area just ahead of the belt. A standard die cannot size that area. In your case, since you're using brass that has been fired in a different chamber, you may benefit from the collet die right away. I purchased the Larry Willis version. I have no affiliation with him or his company but like his product, it has saved me money in the long run.

http://www.larrywillis.com/

Scorch · March 10, 2017, 08:13 PM

What you are seeing is very common on rebarrels. You have a tight chamber and throat.

Never fails, some guy will get all heated about the new chamber not accepting his favorite handloads or, even better, showing pressure signs with the same load he has been firing for years. Had a customer years ago that was upset he was going to have to start his load development from scratch with a new barrel. The original barrel's throat was burnt for almost 10"! His handloads were waaaay overloaded, but with all that freebore he showed no pressure signs.

Stats Shooter · March 10, 2017, 08:29 PM

Quote:

Had a customer years ago that was upset he was going to have to start his load development from scratch with a new barrel. The original barrel's throat was burnt for almost 10"! His handloads were waaaay overloaded, but with all that freebore he showed no pressure signs.

Yea, I wasn't/am not upset at all. A tight chamber is a good thing. And I had planned to start all new load development....Also, I knew that even if the new chamber accepted my old loads, they may shoot like crap.

I was just surprised that I couldn't chamber FL sized brass fired in the old chamber. Basically my old RP brass is useless....It has been fired a few times so no worries, just something I wasn't expecting.

Stats Shooter · March 10, 2017, 08:43 PM

I think I might have found the reason. I say this because it is the only demension I can definitively say the old brass is larger than the factory ammo and brass fired in the new chamber. It "may" confirme the suspicion of post #2.

The factory ammo after being fired in the new chamber measures 0.5085" in diameter above the belt and will chamber and extract effortlessly. My old resized brass measures 0.5125...So a difference of 0.0040 in the usual "bulge" area. Is that enough? It may be in this case.

FIFW SAAMI is 0.5135 so both are within spec.

RC20 · March 13, 2017, 10:48 AM

You have the basic issue going that

1. Your old chamber was longer headspace than the new one.

2. Your brass had fired formed to that.

3. You did not move the shoulder back far enough for the new chamber.

You have two choices

1. Loosen up the headspace on the new chamber (this takes experimenting and I don't think it is worth it but its one way.

2. What you really need to do is check the shoulder dimension OAL on the fired old brass from the old chamber, then start bumping it back until it fits the new gun.

Once you have that established, you do all of them, the next time you fire it in the new chamber and its fire formed to that chamber

Bump it back .002 or .003 from there and you are set.

If you don't have the old chamber (or gun or barrel) there is no need. to match them.

For the new chamber, you measure the shoulder, then bump back until it is .003 less.

What you do need is the Hornady device that attaches to the micrometer blade and then the set of shoulder adaptors that go on it so you can see what is going on.

Setting re-sizer dies without it is possible, but getting repeat results is very hard.

Each time you size a case, you need to measure the shoulder before resize it, measure the shoulder and keep adjusting the die until it bumps back .003.

Don Fischer · March 13, 2017, 08:57 PM

Little something about belted magnum's. They headspace on the belt. As a result some with a sloppy chamber will start head separation you can easily see after a few rounds. Easy fix Partial re-sizing tighten's up the case to the chamber it's fired, almost like moving the head space to the shoulder area!

Huffmanite · March 14, 2017, 07:17 AM

Recently bought a Savage Axis xp II HB in 6.5 creedmore. Also own a Howa I had rebarreled to 6.5 CM. about 6 months ago. Brass I've used for several reloadings or more in the Howa will not chamber in my newly acquired Savage. Dispite how much I resize it, attempting to remove the very slight budge towards end of rim of my used brass. New ammo or reloads with new brass chambers and extracts just fine in my Savage.

RC20 · March 14, 2017, 06:34 PM

Quote:

Little something about belted magnum's. They headspace on the belt. As a result some with a sloppy chamber will start head separation you can easily see after a few rounds. Easy fix Partial re-sizing tighten's up the case to the chamber it's fired, almost like moving the head space to the shoulder area!

I think what occurs is that the initial head space is set by the belt, but then the case fire form so the chamber.

Supposedly you can then measure to the shoulder, bump it back the minimal amount and ok.

Still the issue of the belt down there and any bulge you can size out?

Stats Shooter · March 14, 2017, 07:15 PM

Quote:

RC20: I think what occurs is that the initial head space is set by the belt, but then the case fire form so the chamber

Yes: Initially a bottleneck belted mag cartridge like the .300 wm, the .338 wm, and 7 mag, initially headspace off the belt with new brass or factory ammo. After they have been fired once, they can then headspace off the shoulder. The only two cartridges that headspace off the belt every single time are the .375 HH mag because it has such a small shoulder, and the .300 HH mag because it tapers down to the neck rather than a well defined shoulder.

In fact, the headspace gauges I used when building the rifle and putting on the barrel are the exact same ones you would use for a .375 HH, .338 wm, .300wm, 7 mag..Or any other belted mag I am leaving out.

You could use FL sizing dies and collet dies to get the brass back to factory SAAMI spec and headspace off the belt but it would over work the brass and likely not give the best accuracy....If you are a hand loader like me.

March 10, 2017, 04:41 PM	#1
Stats Shooter Senior Member Join Date: August 26, 2016 Location: North Dakota Posts: 1,636	Is This Common with a rebarrel? So I built my savage 110 .300 wm into a target rifle. It is in a Chassis stock and takes magazines. I put a Shilen #8 28" barrel on it. I headspaced it using the barrel nut and Foster's gauges. It will close easy on the go gauge and about half way on the no go.... I'm pretty sure that's about perfect. I torqued the barrel nut to 70 ft lbs. Now, the new chamber will barely accept my older brass from my previous rifle. I FL size it using RCBS dies and she'll holder, sizing it down until it touches the shell holder. I do not cam-over. The new chamber easily accepts new factory ammo, I bought a box of "cheap" Winchester 150 gr ammo and fired all 20. No problems at all. The fired shells will easily rechamber that were fired in the new chamber. My chamber gauge says that they all grow to 2.2715 exactly from, (with respect to the win factory ammo average) 2.2560.... Which means the shoulder grew out .0155. After 20 firings, the old sized brass will chamber, but I have to tap the bolt with a rubber mallet to get it back out. I noticed some scratches on the old, hard to extract, brass after extraction, but the shoulder diameter is ten thousandths smaller than the new fireformed brass. I have measured from case head to datum but I'm afraid measurement error is too high for me to extract meaningful information. It isn't a huge deal, I'm going to need brass anyway, but I was going to use the old brass to do jump/jam development so that I didn't have to work the new stuff. Last edited by Stats Shooter; March 13, 2017 at 08:59 PM.

March 10, 2017, 08:13 PM	#3
Scorch Senior Member Join Date: February 13, 2006 Location: Washington state Posts: 15,248	What you are seeing is very common on rebarrels. You have a tight chamber and throat. Never fails, some guy will get all heated about the new chamber not accepting his favorite handloads or, even better, showing pressure signs with the same load he has been firing for years. Had a customer years ago that was upset he was going to have to start his load development from scratch with a new barrel. The original barrel's throat was burnt for almost 10"! His handloads were waaaay overloaded, but with all that freebore he showed no pressure signs. __________________ Never try to educate someone who resists knowledge at all costs. But what do I know? Summit Arms Services

March 10, 2017, 05:15 PM	#2
AllenJ Senior Member Join Date: December 11, 2009 Location: Northern California Posts: 1,766	My experience with belted magnum cases is that after 4 or 5 firings they'll need to be put through a collet die to resize the area just ahead of the belt. A standard die cannot size that area. In your case, since you're using brass that has been fired in a different chamber, you may benefit from the collet die right away. I purchased the Larry Willis version. I have no affiliation with him or his company but like his product, it has saved me money in the long run. http://www.larrywillis.com/

March 10, 2017, 08:43 PM	#5
Stats Shooter Senior Member Join Date: August 26, 2016 Location: North Dakota Posts: 1,636	I think I might have found the reason. I say this because it is the only demension I can definitively say the old brass is larger than the factory ammo and brass fired in the new chamber. It "may" confirme the suspicion of post #2. The factory ammo after being fired in the new chamber measures 0.5085" in diameter above the belt and will chamber and extract effortlessly. My old resized brass measures 0.5125...So a difference of 0.0040 in the usual "bulge" area. Is that enough? It may be in this case. FIFW SAAMI is 0.5135 so both are within spec.

March 13, 2017, 10:48 AM	#6
RC20 Senior Member Join Date: April 10, 2008 Location: Alaska Posts: 7,014	You have the basic issue going that 1. Your old chamber was longer headspace than the new one. 2. Your brass had fired formed to that. 3. You did not move the shoulder back far enough for the new chamber. You have two choices 1. Loosen up the headspace on the new chamber (this takes experimenting and I don't think it is worth it but its one way. 2. What you really need to do is check the shoulder dimension OAL on the fired old brass from the old chamber, then start bumping it back until it fits the new gun. Once you have that established, you do all of them, the next time you fire it in the new chamber and its fire formed to that chamber Bump it back .002 or .003 from there and you are set. If you don't have the old chamber (or gun or barrel) there is no need. to match them. For the new chamber, you measure the shoulder, then bump back until it is .003 less. What you do need is the Hornady device that attaches to the micrometer blade and then the set of shoulder adaptors that go on it so you can see what is going on. Setting re-sizer dies without it is possible, but getting repeat results is very hard. Each time you size a case, you need to measure the shoulder before resize it, measure the shoulder and keep adjusting the die until it bumps back .003.

March 13, 2017, 08:57 PM	#7
Don Fischer Senior Member Join Date: March 2, 2017 Posts: 1,868	Little something about belted magnum's. They headspace on the belt. As a result some with a sloppy chamber will start head separation you can easily see after a few rounds. Easy fix Partial re-sizing tighten's up the case to the chamber it's fired, almost like moving the head space to the shoulder area!

March 14, 2017, 07:17 AM	#8
Huffmanite Senior Member Join Date: February 17, 2006 Location: Northeast of Houston, Tx Posts: 393	Recently bought a Savage Axis xp II HB in 6.5 creedmore. Also own a Howa I had rebarreled to 6.5 CM. about 6 months ago. Brass I've used for several reloadings or more in the Howa will not chamber in my newly acquired Savage. Dispite how much I resize it, attempting to remove the very slight budge towards end of rim of my used brass. New ammo or reloads with new brass chambers and extracts just fine in my Savage.