Okay to share brass between 2 rifles?

[WinJim1863]

I shoot 6.5 CM and now have two rifles in that caliber- Tikka T3x TAC and Christiansen Arms BA Tactical. I full length size and have planned to use the same brass (Lapua) in each rifle. Now I am questioning that. I check concentricity (at ogive) after each loading. I have been down to averaging < .001 on some loadings (usually 50-80 rounds depending on match) and always average under 0.0014. I have been pleased with that but now its all gone sideways. On my last loading I averaged 0.0021- within that group however I had one at .005 and several at 3 to 4 thou.
The only thing i've changed in my reloading process is lube- I have gone to lanolin from Frankford Arsenal pump spray- can't imagine that would explain it.
Could the problem be that I am now using the same brass in both rifles? The chambers in the two are very different- CA very tight chamber, Tikka very long throat. I have felt that with full length sizing that wasn't the problem but maybe Im wrong. The CA is pretty new as is the brass so the runout problem started about the time I began using same brass in both rifles.
I will appreciate any advice and help,
Thanks, Jim

 

[Milo 2.5]

I shoot 6.5 CM and now have two rifles in that caliber- Tikka T3x TAC and Christiansen Arms BA Tactical. I full length size and have planned to use the same brass (Lapua) in each rifle. Now I am questioning that. I check concentricity (at ogive) after each loading. I have been down to averaging < .001 on some loadings (usually 50-80 rounds depending on match) and always average under 0.0014. I have been pleased with that but now its all gone sideways. On my last loading I averaged 0.0021- within that group however I had one at .005 and several at 3 to 4 thou.
The only thing i've changed in my reloading process is lube- I have gone to lanolin from Frankford Arsenal pump spray- can't imagine that would explain it.
Could the problem be that I am now using the same brass in both rifles? The chambers in the two are very different- CA very tight chamber, Tikka very long throat. I have felt that with full length sizing that wasn't the problem but maybe Im wrong. The CA is pretty new as is the brass so the runout problem started about the time I began using same brass in both rifles.
I will appreciate any advice and help,
Thanks, Jim

Not wanting to get into a lengthy post, it is usually best not to share brass between precision rifles. Can it be done, yes it can.
Think this way, you are measuring runout after sizing and seating bullets, brass should be the most concentric it will ever get coming from your chamber(even over new), so measure some fired brass, from each chamber get an inside and outside neck readings, if it tells you a story, you will know.

 

[lte82]

Take a case and run 5 full power loads through it on one gun and see if it works ok in the other. Then swap guns and try again. If the case chambers and extracts easily after firing every time then you are good. If it doesnt, you should keep the brass separate.

 

[ShtrRdy]

OP - you have been able to load some incredibly low runout ammo. If you have some time, would you mind listing the steps you use and the type of dies and press? -- Todd

 

[Sheldon N]

I would not suggest sharing brass between rifles unless they were cut with the same reamer, or unless the fired brass for both came out close to identical (headspace, shoulder diameter, base diameter, etc). Otherwise you are going to be fighting with brass springback when sizing and creating problems for yourself.

@ShtrRdy if you want an easy way to make very low runout ammo, try FL size (non bushing die) with the expander ball removed, followed by an expander mandrel to set neck tension. Pretty hard to screw that one up no matter which press or dies you use.

 

[Milo 2.5]

I would not suggest sharing brass between rifles unless they were cut with the same reamer, or unless the fired brass for both came out close to identical (headspace, shoulder diameter, base diameter, etc). Otherwise you are going to be fighting with brass springback when sizing and creating problems for yourself.

Good points, I did not want to get into that, if I was sharing brass, I think runout would be my last concern. Come to think of it, it is anyway, I have a 21st Century gauge that collects serious dust.
I wish someone credible would run a true test on it. I know from my experience, 003" runout does not show up downrange, actually the number is higher. With decent equipment, .002" runout is a high number, but shooting from a bipod, not many of us would be able to tell the diff between .0015" or lower, or .002".

 

[bschneiderheinze]

I run the same brass in two rifles but they are the same actions, same barrels, reamers and length. Still their is some variance because one has a few more rounds on it than the other.

 

[WinJim1863]

OP - you have been able to load some incredibly low runout ammo. If you have some time, would you mind listing the steps you use and the type of dies and press? -- Todd

I don't know if copying my process is a good idea given my current problem but:
-Tumble brass, Frankford Arsenal, SS pins, Simple green, dish soap, Lemishine
-Anneal for each loading, homemade machine
-Full length size. Used to use Hornady then Redding w/ floating bushings (.290 for 6.5 CM) but wasn't happy with case neck concentricity so have gone to Forster with custom honed neck at .290 (I have a .291 on order, will probably end up with very little neck tension). Forster Die is much tighter through the length of the die than Hornady or Redding (not sure that is good or bad, just different- I took it to Forster and they re polished it).
-Expander ball out of sizer. after sizing I use the Sinclair Mandrel to expand neck (.263 as I remember)
-Check cases for length, trim if needed. Lapua cases not stretching after 7 firings
-Chamfer necks w/ RCBS ELD.
-Final hand wash, dish soap and simple green
-Check case neck runout. Fired cases come out of chamber almost prefect, runout actually increases with sizing but not much.
- Have been loading with Redding turret press. Recently visited Forster and came back with their Co Ax press. In my side by side tests it is no better than Redding in terms of runout but I really like it.
- I seat with a Forster micro seating die. Used to use Hornady but found it drifted.
I don't turn necks. Have thought about it several times. Now with Lapua cases I don't see the need. they typically are within .0005 variation around the neck.
There are a thousand ways to load; this is just what I've settled on.

 

[WinJim1863]

Thanks to all for replies. I will not share brass given how different the chambers are and see if that works. Also, Ive been experimenting with seating depth and have bullets (Berger Hybrid) .020 off lands in Tikka. Maybe I need to check them against the old caliber width in case neck rule??

 

[Milo 2.5]

- Have been loading with Redding turret press. Recently visited Forster and came back with their Co Ax press. In my side by side tests it is no better than Redding in terms of runout but I really like it.

Lol, same exact thing here on T-7 to coax. Now a die switch did yield slight gains.
Just out of curiosity, what is the concentricity tool you are using, because these are not created equal?

 

[Va_Gentleman]

Some general idioms of life is what I would apply to the question:

1. Never cross the streams

2. Never rub another man's rhubarb

 

[Sheldon N]

-Full length size. Used to use Hornady then Redding w/ floating bushings (.290 for 6.5 CM) but wasn't happy with case neck concentricity so have gone to Forster with custom honed neck at .290 (I have a .291 on order, will probably end up with very little neck tension). Forster Die is much tighter through the length of the die than Hornady or Redding (not sure that is good or bad, just different- I took it to Forster and they re polished it).
-Expander ball out of sizer. after sizing I use the Sinclair Mandrel to expand neck (.263 as I remember)

@ShtrRdy See, what did I tell you?

 

[buffybuster]

As previously stated, unless the chambers are cut by the same reamer consecutively and the headspace set the same, it usually does not work too well. What you end up doing is setting up to the smaller chamber, which is great for that chamber but sloppier for the larger chamber and it overworks your brass. If you try some middle compromise then you will get stiff extraction or some other issues.

To eliminate the possibility of mixing brass, I use different headstamps or at the very least mark the cases, when only one brass source is available (6.5x47L)

 

[WinJim1863]

Lol, same exact thing here on T-7 to coax. Now a die switch did yield slight gains.
Just out of curiosity, what is the concentricity tool you are using, because these are not created equal?

Milo,
I use the Hornady Concentricity gauge and occasionally check with the Sinclair case gauge. Admittedly not the highest tech and if you have a better answer please post. Jim

 

[Vinootz]

Better not to mix brass if they are precision rifles. Keep in mind it may take brass two to three firings to fully form to the chamber.
And brass hardness evolves changing the springback. Bullet seating depths may come into play also. And I thought this reloading thing would be fairly simple-LOL.

 

[Milo 2.5]

Better not to mix brass if they are precision rifles. Keep in mind it may take brass two to three firings to fully form to the chamber.
And brass hardness evolves changing the springback. Bullet seating depths may come into play also. And I thought this reloading thing would be fairly simple-LOL.

4-5 yrs ago I was splitting brass between 2 - 6.5x47's, over 700 pcs, though I used 2 diff sets of dies, with different settings, I cannot say there was any accuracy degradation because I did so. One rifle was more accurate, but I am positive it was the load and not the brass, the more accurate rifle never suffered.
Today I load for 4 dashers, all chambered by the same smith. Even though I have 3, I use one sizing die, 3 different seaters. 2 of the rifles are so accurate, mixing brass would be stupid with those. The other two I could share brass and never miss a lick.
I think chamber dimensions as I think you alluded too would be the deciding factor for me. But if I added a 2nd rifle using the same case, I surely would not mix 4 times fired brass with new to accommodate the 2nd rifle.