Taking apart 97 rounds of 6mmBR--updated after range trip

[carlsbad]

Re: Taking apart 97 rounds of 6mmBR

Ok. I understand what you were saying about "hearsay". But this isn't my first rodeo. I didn't just grab one load and go with it. I searched quite a bit and found some loads from reliable sources. Although hot, it wasn't dangerous or embarassingly hot. Via PM, it has been suggested that my real problem may be that my firing pin needs bushed in my Rem 700 bolt and my load wasn't too hot at all. I'll figure that out friday.

No, I wasn't shooting for 3100 or 3300fts. I was shooting for 2600 to 2800 and believe the rounds I took apart were still likely below 3000. No, I didn't feel lucky that I didn't lose an eye. I fired 2 more rounds after I identified that they were a little hot. No, I don't have to have a threat to life and limb to take ammo apart--maybe a slight threat to the throat of my new barrel. Perhaps this seems radical to some of you but with the right equipment it is pretty easy. I've got a bunch of old 9mm that is coming apart soon. And as a single guy I can set up and do it in the living room in front of the TV.

So I appreciate all the help and I apologize if I lashed out a bit yesterday. Had a bad day on twitter when a radical group took a comment I made to an astrophysicist friend in Australia out of context, labeled me a hater of their "cause", and mass attacked me. Blocking attackers was a lot more trouble than reloading 100 rounds.

I do spend a lot of time on twitter where you're limited to 140 characters and from time to time I leave out a lot of minor details. Maybe it wasn't clear that I did take more than one load with me but I had picked the wrong starting point so I came home to fix it. If I had left out the experience and just asked for starting loads for my rifle, I could have avoided a lot of commentary but I like to share my experience and read about other's experience as well.

Bottom line is I do recognize this forum as very talented and expert. There are a lot of other forums out there where I could be posting and I've read them all. I think this one has the most potential. I do appreciate all the help and hope to be a member of the community for a long time going forward. Once I find the right load, I'll post it in the "favorite loads" thread.

I'm suffering from the powder shortage. I know some of the suggestions here are load development suggestions. I'm not really looking for the perfect load yet because I don't have enough powder to take advantage of it. I just want to get the rifle shooting in the 2700fps range and have some fun plinking steel at 900 yds. Once I get more than 1 lb of powder I'll develop an optimal load for that powder. I know, some will suggest I should wait but I have been waiting a month and want to get out there with the new rifle. Then I'll probably put it away until I find powder.

Thanks for all your help.
--Jerry

 

[saunaking]

Re: Taking apart 97 rounds of 6mmBR

The powder shortage is hurting all of us on what we want to use. I have both Varget and 8208 to use, but simple burn rate charts tell me that 8208 will be too fast for the heavy 6mm bullets. I would look for an alternative to Varget that has a similar burn rate.

It is not the first "rodeo" for most if not all of those who have provided advice to you. My guess is that everyone here has worked up loads for a 6BR and is speaking from experience when they offer advice. I use my 8208 for the lighter bullets (65 - 90 grain) in a 6br and 6 brx with great results on my varmint loads.

 

[dkhunt14]

Re: Taking apart 97 rounds of 6mmBR

First off cratered primers in a Remington doesn't necessarily mean he is hot. I called and talked to Eric from Berger and asked why the loads for 300 WSM were so low. He told me for liability sake they had to keep published data low for safety. If you look at a Hornady loading manual from say 40 years ago and look at a new one; I bet the new one has lower max loads in it. Hornady used to list some pretty stiff loads in it compared to other manuals. Another thing about using peoples loads are barrels do not always allow the same powder charge. Bullets also can be fatter and if the throat is longer you can shoot more powder. There are a lot of factors that decide pressure. Yes he started too high, but he might end up there close if he bushes his bolt. I have seen different primers blank in the 6 BR and the Dasher. Some of these were not with hot loads. Federal will blank the quickest and I think the BR4 is the toughest primer. This is all based on what I have tested or seen in competition. I only ever saw one BR4 primer blanked and that was with a REM action. Carbon in the throat will really raise pressure. Matt

 

[jhord]

Re: Taking apart 97 rounds of 6mmBR

That was my experience with 8208 in the 6BR. IMO it's more of a 68-80grn. bullet powder, and even then sometimes it would get me in trouble. I found it to be a very "spiky" powder. The pressure curve seems very non-linear near max loads. And the big bullets would get you in trouble even faster.

I have both Varget and 8208 to use, but simple burn rate charts tell me that 8208 will be too fast for the heavy 6mm bullets. I would look for an alternative to Varget that has a similar burn rate.

 

[carlsbad]

Re: Taking apart 97 rounds of 6mmBR

Saunaking,
You're the first to express the opinion (to me) that 8208 would be too fast. Because it had been recommended so highly for 6mmBR I figured that varget was at the slow end of the range. As a result, I've passed on VV N150 that is available, being slower than Varget. maybe I should reconsider.

I know the people here are seasoned veterans, some much more than me. but I've seen a lot of kids showing up very green. Since I just showed up there are probably some wondering if I'm a kid with my first rifle.

thanks,
jerry

EDIT: Now I have two votes for 8208xbr being too fast. Dang, now I have to take all those bullets apart again. (Just kidding) But I'm thinking I may just go buy that N150.

 

[nosualc]

Re: Taking apart 97 rounds of 6mmBR

Jerry,

8028xbr is a bit out of the norm for a 6BR with 108s (and as others have mentioned, perhaps a bit fast for that bullet). http://forum.accurateshooter.com/index.php?topic=3738337.15

We've all been there: trying to make things work with what you have.

I was trying to emphasize that when you go off the reservation a bit, you need to make double sure you use caution. The 10% rule of thumb is a prudent methodology. Although a cratered primer is sometimes a false indicator of pressure due to sloppy firing pin fit, your description was "severe cratering", which would given me pause.

Send your bolt to Greg at Gre-Tan rifles to be bushed. Send it monday, you'll have it back by friday. It's the best deal/service in gunsmithing. http://www.gretanrifles.com

Sorry that you had a bad day; my intent wasn't to make it worse.

-nosualc

 

[carlsbad]

Re: Taking apart 97 rounds of 6mmBR

DKHunt,
Thanks for your comments. It is a shame I didn't get any chrono data for the 3 rounds I shot. I'm a single dad and had to drop my son off that morning so when I got to the range it was already hot. I almost turned around and went home since all the lanes were full. But the rangemaster recognized me and made a spot for me so I thanked him and did the best I could under the circumstances.

Before I go back to the range (after Friday) I'll bush the firing pin and eliminate the craters. Although the primers were flattened around the circumference, I've seen worse.

I'd like to make the Rem BR primers work since I bought a lot of them. but if they don't, they won't be hard to sell.

As for published loads being low, maybe my loading manuals are old but most don't have any data for 6mmBR. VV does have some load data on their site. I agree in our litigious society the lawyers may be specifying the max load instead of the experts.

thanks,

--Jerry

 

[carlsbad]

Re: Taking apart 97 rounds of 6mmBR

Nosualc,

Thanks. It's my responsibility to keep a cool head so the apology belongs to me.

I do my own gunsmithing (and do a little for others). But I work a full time job too. Should get the bushing installed this weekend.

Thanks, Jerry

 

[dkhunt14]

Re: Taking apart 97 rounds of 6mmBR

H4895 works good in the Dasher with the heavy bullets so I imagine it would work good in a BR. That may be a little easier to find then Varget. It seems Varget at times gets real hard to get. It is a real popular powder. Maybe the guys are right about the 8208 powder, I have never used it Because I started with Varget and that is all I use. An 8 pounder lasts a long time in a Dasher. Make sure the carbon is out of the throat, Depending on how many rounds that other guy fired it could Have carbon in the throat. You guys are right he should load one or two and work up. I didn't mean to sound he was ok but it could be other things also. Matt

 

[saunaking]

Re: Taking apart 97 rounds of 6mmBR

The only reason I mentioned being too fast (8208) is that I have tried it in both a 6br and a 22br with heavy for caliber bullets and found to be way slower over my chronograph than powders in the Varget burn rate (4895, r15 and 748) before pressure signs showed up. It is a great powder for the lighter/shorter bullets in the 6 BR. Good luck with the load work.

 

[carlsbad]

Re: Taking apart 97 rounds of 6mmBR---updated with data

Went to the range with loads from 26 to 28 grains of 8208 xbr and the Berger 108s. Average Velocities were as follows:

26 grains 2560
27 grains 2635
27.5 grains 2670
28 grains 2710

I didn't take anything higher but it seems clear the 29 grain load I took with me the first time wasn't over 2900 fps--which was my target.

I still had cratering AND perforations. The first 27 grain round I fired, with a measured velocity of 2635, perforated. Thank God for chrono data or I would have been scratching my head AGAIN.

I did have a few rounds primed with CCI and they didn't crater nearly as bad or perforate. They also don't flatten around the circumference nearly as much as the Rem 7.5.

So I'll bush my firing pin and try the 7.5s again (yes, I bought a lot of them in the shortage). If that doesn't work I'll move to the CCIs.

And I found an 8 lb jug of VV N150 and pulled the trigger so that will be the powder I develop loads for. Can't really complain about the 8208xbr though. I was just shooting 3 shot groups (which isn't very reliable in my opinion) but group sizes were .17 to .26 and didn't really correlate much with load. I'll do more scientific load development with the new powder.

Going up the hill to 900 yards I had a few misses so maybe the slower powder will perform better in that aspect.

Thanks to everyone for their help. Sorry my original post was written in a way that stirred up so much discussion.

--Jerry

 

[GrocMax]

Might want to double check headspace, case sizing to headspace, and firing pin protrusion before going further. If you are piercing primers at lower loads something is not right.

 

[carlsbad]

Good thought to check the headspace since this is the first range session with this rifle since I built it. I set the headspace tight--go gauge goes. no go gauge not even close. go gauge with .002" tape on it won't go. Just checked it and no change.

Firing pin on this donor action appears a bit short in that I had a couple of FTFs and all strikes on the FTFs appear on the shallow side.

I think the problem is the excessive clearance on the firing pin combined with very soft face on the Remington primers. Should be fixed when I bush the pin. I'll check the pin for length and replace it if necessary while I have the bolt apart.

thanks,
Jerry

 

[Old Navy]

You will not believe the difference after having the pin bushed. You will not believe the difference using the right powder for the bullet. Later! Frank

 

[CJ6]

Neck clearance ?

 

[carlsbad]

270. Using Lapua brass out of the box.


--Jerry