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Post by Dave W on May 8, 2009 22:00:47 GMT -5
I have been shooting Rel-7 sabotless in the .45 for a couple weeks now. I have not been able to get anything sub MOA out of it with the 250 BE at 200yds, the 250 SST shoots poorly at both 100 & 200yds. The last 11 shots over a couple sessions averaged 2438fps, really not the speed I was looking for or the accuracy with 250gr bullets. The 200yd groups measured: 2.562" for 3 shots @ 57gr 3.94" for 3 shots @58gr 3.04" for 4 shots @57.5gr Tugged the 4th shot a little in this group tonight, so this might have been a little better.  I shot the 56gr load at 100yds(lower target) last Sun. with the 275BE, thought this might be close if I could get the vertical spread out of it with a little more powder. So tonight I tried 56.5gr at 200yds. 4 shots into 1.852", velocity was 2402fps.  This powder seems to be more efficient with the heavier bullet as you can see by the charge weights and velocities. I found the same thing in my experiences with the 50 cal. |
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Post by sw on May 8, 2009 22:59:14 GMT -5
I don't know your cleaning routine. If you start with a clean barrel each time and use that 1st shot as your fouling shot, the groups would be smaller on the 2 #'d tgts.
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Post by rbinar on May 9, 2009 4:28:42 GMT -5
8-)I can understand your concern for how the load changes speed. It does not seem normal that a mere grain of powder can make 100fps difference with a 275 grain bullet. Normally I’d be wondering about this myself. However I’ve dealt with it before and it has more to do with efficiency than a pressure problem.
That can be said because if it was loaded right there is no way 57 grains at 2400fps is at a serious pressure point. By any measure this load is mild. That’s not to say I’d jump 5 grains just to see what happens, far from it. Still there is no accelerated pressure problem here. What is happening is progression. That is at a certain point smokeless pressure depends to some degree what has happens in the past period of ignition.
In sabot-less shooting there is little inertial and frictional resistance so it may take some amount of powder to have initial efficiency. When that point is reached you may see a jump. To get around this problem cases that shoot a limited amount of powder or pressure have the requirement that the bullet be firmly crimped by the case. This provides the resistance for good initial ignition.
You can’t crimp the case in a muzzle loader so you have to be aware this can happen when crossing from one speed to another. It would be no problem whatsoever if it were not for the fact this problem is similar to duplex saturation. Shooting a duplex this must be avoided completely. It is a sign of a much more dangerous occurrence where a point has been reached where powder speed is changing too fast.
With the 250 grain bullets you are actually shooting too slow. In a well crimped case with some frictional resistance a 250 grain bullet would normally make about 2500fps with 57 grains of powder. Normal load pressures are not more than 42,000psi at this speed. So feel free to move up slowly.
Sure you want to ensure everything is safe but there is little reason to shoot slow and inaccurate. Moving to about 2525 to 2575fps will likely help both conditions.
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Post by Dave W on May 9, 2009 5:32:41 GMT -5
I don't know your cleaning routine. If you start with a clean barrel each time and use that 1st shot as your fouling shot, the groups would be smaller on the 2 #'d tgts. I noticed the first shot went high in both groups also. On the 275 BE, the first shot was on a cool barrel after an extended cool down. The 250 group was shot after a SST string. As for the cleaning routine-nothing, load and shoot. |
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Post by Dave W on May 9, 2009 6:00:58 GMT -5
8-)I can understand your concern for how the load changes speed. It does not seem normal that a mere grain of powder can make 100fps difference with a 275 grain bullet. Normally I’d be wondering about this myself. However I’ve dealt with it before and it has more to do with efficiency than a pressure problem. That can be said because if it was loaded right there is no way 57 grains at 2400fps is at a serious pressure point. By any measure this load is mild. That’s not to say I’d jump 5 grains just to see what happens, far from it. Still there is no accelerated pressure problem here. What is happening is progression. That is at a certain point smokeless pressure depends to some degree what has happens in the past period of ignition. In sabot-less shooting there is little inertial and frictional resistance so it may take some amount of powder to have initial efficiency. When that point is reached you may see a jump. To get around this problem cases that shoot a limited amount of powder or pressure have the requirement that the bullet be firmly crimped by the case. This provides the resistance for good initial ignition. You can’t crimp the case in a muzzle loader so you have to be aware this can happen when crossing from one speed to another. It would be no problem whatsoever if it were not for the fact this problem is similar to duplex saturation. Shooting a duplex this must be avoided completely. It is a sign of a much more dangerous occurrence where a point has been reached where powder speed is changing too fast. With the 250 grain bullets you are actually shooting too slow. In a well crimped case with some frictional resistance a 250 grain bullet would normally make about 2500fps with 57 grains of powder. Normal load pressures are not more than 42,000psi at this speed. So feel free to move up slowly. Sure you want to ensure everything is safe but there is little reason to shoot slow and inaccurate. Moving to about 2525 to 2575fps will likely help both conditions. Thanks RB, I thought the 57gr load with the 275BE would be in the mid forties but I don't like to seeing abnormal jumps in velocity. I tried going up in charge weight with the 250's, but the groups never tightened up, 57.5gr was where the groups flattened out, might try 57gr with the 275BE to see if it shrinks the group a little. |
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Post by edge on May 9, 2009 6:03:42 GMT -5
Are these "stock" bullets or are they knurled?
How hard are they to get into the muzzle?
My two best guesses are not tight enough in the bore and they are not engraved enough AND/OR not enough initial pressure.
I did not read if you used an over powder wad, but IMO you should.
If you have some N120 try 60 grains with your 250 grain bullet as a comparison, but I would suspect bullet fit first.
edge.
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Post by Dave W on May 9, 2009 6:12:07 GMT -5
Are these "stock" bullets or are they knurled? How hard are they to get into the muzzle? My two best guesses are not tight enough in the bore and they are not engraved enough AND/OR not enough initial pressure. I did not read if you used an over powder wad, but IMO you should. If you have some N120 try 60 grains with your 250 grain bullet as a comparison, but I would suspect bullet fit first. edge. Tighter than normal since I shot it dirty last night, but not overly hard to get down the bore, maybe 70-80 lbs. of pressure to seat on the 275's, a little less with the 250's. Stock- no knurl. I always use two .030 veggie wads when shooting sabotless. No on the N120, one of the powders I have not tried. |
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Post by Dave W on May 11, 2009 21:26:01 GMT -5
Looks like 57gr Rel-7 with the 275 BE might be the ticket. 1.075" CTC @ 200yds. Avg 2457fps  Since 56.5gr was sub MOA for 4 shots and 57gr was well sub MOA for 3 shots at 200yds, this might be an option for people worried about misfires with H4198 in colder climates. I changed one thing tonight, I swabbed between shots, otherwise the routine and components were the same. |
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Post by chuck41 on May 11, 2009 21:39:45 GMT -5
Sure looks like a winner to me. I would be really proud to display 200yd groups like that!!
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Post by rexxer on May 11, 2009 21:58:51 GMT -5
I agree with Chuck Dave, Very nice!!!
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Post by ET on May 11, 2009 22:16:57 GMT -5
Looks like 57gr Rel-7 with the 275 BE might be the ticket. 1.075" CTC @ 200yds. Avg 2457fps Since 56.5gr was sub MOA for 4 shots and 57gr was well sub MOA for 3 shots at 200yds, this might be an option for people worried about misfires with H4198 in colder climates. I changed one thing tonight, I swabbed between shots, otherwise the routine and components were the same. Come on now my Vernier ruler says thats a 1.076" group. ;D ;D Nice shooting. Ed |
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Post by Chris Champion on May 12, 2009 10:55:53 GMT -5
Looking good Dave. Nice shooting
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Post by DBinNY on May 12, 2009 11:50:06 GMT -5
Looks like... Great shooting Dave.
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Post by dougedwards on May 12, 2009 12:30:57 GMT -5
excellent!
Doug
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larry
8 Pointer
Posts: 172
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Post by larry on May 12, 2009 13:08:03 GMT -5
Good shooting Dave ;D Looks like the .45s like 275 bullets sabotless. Larry
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Post by Dave W on May 12, 2009 18:15:01 GMT -5
Thanks guys.
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Post by rexxer on May 13, 2009 20:52:02 GMT -5
Very nice job Dave! I'm glad you stuck with it! Now ,how can you get the 250s to shoot? Different powder?
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Post by Dave W on May 14, 2009 4:24:52 GMT -5
Very nice job Dave! I'm glad you stuck with it! Now ,how can you get the 250s to shoot? Different powder? H4198 works extremely well for me with the 250BE, 59gr @2600fps, problem is nobody has 8 pounders right now. Rel 7 might shoot them also with the right charge weight, I just did not find it. Glad I stuck with it also Rex, I'm going to save the rest of this pound to test in the fall when the temp drops. |
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Post by rangeball on Dec 6, 2012 10:01:06 GMT -5
Dave, did you ever test the RL7 load in colder temps? I know with the nitro it should not have ignition issues but am wondering how the FPS fared over various temps.
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Post by Dave W on Dec 6, 2012 16:32:13 GMT -5
Dave, did you ever test the RL7 load in colder temps? I know with the nitro it should not have ignition issues but am wondering how the FPS fared over various temps. That was the plan but never got around to it.  |
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Post by rangeball on Dec 6, 2012 16:52:27 GMT -5
I know how that goes. I'm real good at making plans. Just finding the time to execute them is the problem  |
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