Cold bore shot(fouled barrel)?

[350Mag]

Was at the range yesterday.

Accura V2 LR
BH 209
CCI 209M
275 gr Parker BE.(MMP black sabot)



100 yards.

I pre-weighed charges from 77 GR up 84 gr.

I shot everything over chronograph.

FYI with a 25 deg F. Temp drop I was loosing 100 fps with BH 209 so Westerns claims that it isn't temp sensitive is bunk. Back when I was shooting in Sept. I was getting 2060 fps with 79 gr charge....it took 84 gr to reach 2060 yesterday.

Using the Chrono I was able to identify a couple of accuracy nodes.

The best being at 79 GRS, 84 Gr.

I shot 3 shots at each charge weight 77,78,79,80,81,82,83,84.

In between groups I would clean out breech plug.

The problem I ran into was 2 x I let the rifle cool right off and the first shot was low.(4-5 inches).

I attributed that to a flyer? But not so sure?

The subsequent 3 shots were in a nice sub 2 MOA group?

The final group was at 300 yards.

Again, the rifle had sat for awhile because I had to relocate and set up bench.

The first shot was 10 inches low.

The next 2 grouped around 4 inches just off the bullseye on 8 inch circle. I was quite happy with that.

The humidity was high so I did notice after the rifle cooled there was a little moisture/dampness at muzzle ( I am assuming from condensation from barrel cooling???)

When I got home I cleaned rifle and fired 2 primers.....and then dry patched it.

Today...

I am going to goto range and fire a cold bore shot @ 250 yards(probably the max range I would consider for game).

Fingers crossed....lol.

If that doesn't work....I am going to load the rifle and bring it home and return the next day and see where cold bore fouled shot hits after sitting overnight.

If I cannot solve this issue I will just have to remember to adjust fire Ona cold bore shot?...and forget about any long range shots.

 

[MrTom]

Welcome aboard 350.

I'm thinking Western's claim on temp is that the powder goes bang in a wide range of temp spreads. Most powders will show differences in velocity between warm weather and cold weather though.....at least that's been my experience with black and the subs including 209.

The cool barrel stuff though is puzzling unless you are cleaning the barrel as well as the plug. Shooting an Accura V2 myself with the 209 powder at 77 weighed grains and a 300 grain bullet/sabot I get about 4 inches of rise on a clean, un-fouled, cold barrel for the first shot at 100 yards. Subsequent shots go right to the point of aim even after running a dry patch thru the barrel when I clean the plug. I do know that the 209 powder seems to offer fliers on clean barrels for the first shot so fouling is a good idea prior to hunting a clean gun.

I hunt and range shoot in a cold state and have never noticed a flier due to a cooled barrel in colder weather so no solution here but hope you get it figured out before your hunting season .

 

[dbowling]

Also if your lighting isnt exactly the same or close a lot of times your chrono can be off quiet a bit.
Also my guns even when shot in very cold weather are never off by more then a inch on a clean cold bore.

 

[GM54-120]

Were the BH209 lot#s the same for now and last Sept? Since you weighed the powder that could be part of the difference.

 

[WV Hunter]

I don't shoot nearly as much as many of the guys here, but I can say that I have not had a "cold fouled bore" issue DURING a range session. Once my bore has been fouled, I don't see that. I have had a clean cold bore flyers, typically no more than 2" away from the group (100yd).

 

[350Mag]

Never had a chance to go today...too windy.

Hopefully tommorow morning...

 

[edmehlig]

I was going to go out myself after work, but the wind really picked up. Hopefully tomorrow afternoon???

 

[350Mag]

Went today ..

Fired 3 shots at 200 yards.

Fired 2 at 300 yards.

All were fired from sitting position...using bipod....all would have been in kill zone on Deer.

Accuracy was fine....no major shift in P.O.I from cold bore to warm.

Very happy with results.