45 degreeish

[OU812]

Well I went out again today with the 300 rum and shot 2 shot groups at all seating depths but the last depth, it was a 3 shot out of curiosity.



L-R
3.670, do not recall which one was 1st
3.655, upper hole 1st, lower 2nd
3.660, upper hole 1st, lower 2nd
3.655. middle hole 1st, lower 2nd, upper 3rd

It's not the group size I'm asking about but rather the 45ish degree angle in which all 4 groups show sign of. I made no scope adjustments, this is once fired brass, neck sized, all other components are of same lot except for primers, these primers were Fed 215 and not the Fed 215 GM as used the day before.


I realize this is a very small sample but the groups were oddly repeatable, what are your thoughts?


Bill

 

[Guest]

That could be heat induced stress, except the last group didn't follow the pattern of the two middle groups. I'm going to suggest you're seeing the plane of harmonic oscillation on this rifle oriented at 45deg to vetical. The barrel is oscillating in its sine wave pattern but not in a vertically oriented wave form, but a 45deg off vertically oriented wave form.

Or maybe your rest/sandbags were moving just the same each time and it was causing slight changes in point of aim/impact? I still think harmonics...

 

[Oldtrader3]

If your groups were more vertical, I would think about the barrel and temperature. My experience with 45* groups is either optic mounts/rings loose or barrel bedding issues? Not enough shots and groups to tell me much yet.

 

[SJB358]

Bill, I would bet on bedding. I am not sure how the pressure point is in your CDL, but the 25-06 CDL I had had an unreal amount of pressure on the barrel and it would not put three shots within 12" of on another. I wish I was exaggerating, but I am not. When I got rid of the pressure point, it slunk down to become a decent shooting rifle. I would imagine it has the same kinda inletting the other Remington's I have, poor at best. The outside of the rifle looked great but when I took it apart, I was amazed at the amount of slop that was allowed in the recoil lug area. I threw pillars and glass at it, then sanded out the pressure point and resealed it. Worked very well and was very easy actually.

I am sure it could be a number of things, but I would do the old credit card trick of shimming it up out of the stock a hair to relieve the pressure on the barrel and see what comes out. I would guess you would see right away if it is actually the bedding/inletting or something else. I would almost bet money on the pressure point though.

 

[FOTIS]

I agree with Scotty. Try the CC trick.

 

[Guest]

I'm with Scotty and Fotis on this one. The 300 RUM produces a lot of barrel heat. To eliminate the problem I had mine glass bedded, free floated and pillars installed. Totally eliminated stock pressure on my barrel. How is the trigger pull on your gun? I had mine re-worked and reduced from 3.5lbs to 2.5lbs, that really helped my groups as well.

Don

 

[OU812]

I wanted to say thanks to everyone for your time and thoughts on this issue and this morning I solved my mystery, with a bonus. The Remington pressure point was the first thing to go once I decided to keep the rifle so the barrel is free floated. Last night I loaded up 6 more round and this morning headed to the range. The temp was 58 degrees, overcast, calm wind, load data as follows.

94.5 Retumbo
Fed 215 GM primer
3.670 Col
200 AccuBond

Figured out that yesterdays 45 degree 2 shot groups was caused by the way I normally do not hold the rifle at the bench but for some reason was doing so. This picture is of the 3 shot group I shot this morning with the way I normally hold the rifles when shooting from a bench. The bonus came via chrono results, very very pleased with the speed. The tear in the paper below #3 is from a staple.

Bill

 

[SJB358]

Holy smokes Bill, yeah, I would say your done buddy! No elk is going to slip through them AB's.. Man, that is fast too.

 

[OU812]

Holy smokes Bill, yeah, I would say your done buddy! No elk is going to slip through them AB's.. Man, that is fast too.

Thanks Scotty, I am very happy with the speed as it seems I usually end up with the slower barrels, not this time. :grin:

Chrorno was at 12 measured feet figured that was far enough.


Bill

 

[SJB358]

Bill, I gotta say I was pretty jealous of Brian's Model 70 300 RUM.. I was hoping he didn't like it and wanted to rid himself of it. I don't think it will happen now though. The 300 RUM is a pretty awesome 30 cal.. Yours is really performing for all it is worth. That is some great performance. That 200 AB gets to 600 yards, right now. Pretty impressive stuff.

 

[Guest]

Bill,
Good Job, I'd say your there buddy. Is that new brass or fired and re-sized brass with that load?

Don

 

[nvbroncrider]

Sweet that's definitely some thump on both ends of that one.

 

[OU812]

Bill,
Good Job, I'd say your there buddy. Is that new brass or fired and re-sized brass with that load?

Don

Thanks Don. I really lucked out with this rifle. It's been easy to load for thanks to you guys. Today's group was 3 times fired neck sized brass. The case stretch has been minimal and as of today after re-sizing I can still do at least 1 more firing before trimming and annealing will be needed.

94.5 gr of Retumbo shows no sign of pressure and I have no idea what max is for this rifle but with the speed I'm getting why bother?

Bill

 

[JD338]

Good work Bill. Way to stay on it.

JD338

 

[Woodycreek]

Bill,
Good Job, I'd say your there buddy. Is that new brass or fired and re-sized brass with that load?

Don

Thanks Don. I really lucked out with this rifle. It's been easy to load for thanks to you guys. Today's group was 3 times fired neck sized brass. The case stretch has been minimal and as of today after re-sizing I can still do at least 1 more firing before trimming and annealing will be needed.

94.5 gr of Retumbo shows no sign of pressure and I have no idea what max is for this rifle but with the speed I'm getting why bother?

Bill

That 94.5 gr is giving great speeds and accuracy. I would bet anything over 95 gr of Retumbo would be darn close to red lining. I have pushed all the way to 96, but I think that was a slow lot of Retumbo.

 

[Guest]

Bill,
That is impressive with re-sized brass. I got 3200+ with 200 AB & re-sized brass with a really good group but was wiping the case heads from pressure. I too was at 94.5-95.0 Retumbo, But got better accuracy with RL-25.

Don

 

[OU812]

Don and WC,

I ran up to 95 gr retumbo with the same no pressure signs results. I was hoping for 3150 but I'll take the higher speed with no pressure issues what so ever, kind of best of both worlds.

I did load up some RL-25 to try this morning but with what I observed with retumbo I never even fired one of the rounds. Might have gotten a little better accuracy but the 3rd shot could have been me or heat as I fired all 3 shots back to back to back.

Bill

 

[Guest]

Bill,
If the barrel got pretty hot with 3-shots that was probably the problem. I would bet if you take your time and allow the barrel to cool between shots it could help improve the group or eliminate it from the equation as a problem.

Don

 

[JD338]

Bill,

I just bought one of these today....
http://www.bullsbag.com/Multi_Purpose_B ... ag_s/6.htm

JD338

 

[OU812]

Bill,

I just bought one of these today....
http://www.bullsbag.com/Multi_Purpose_B ... ag_s/6.htm

JD338

I saw one of those at the range the other day, looked like it would work very well. Do give a report once you use it will ya?


Bill