#1
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20 Practical 4443 FPS ....OOPS!
I screwed on a new Criterion 20 Practical barrel two weeks ago and went out today for the second round of load development. I ordered the barrel with a blended brake by Criterion. While my other 20P Criterion barrel without brake does ok as far as affecting the sight picture (15lb rifle) it does not allow seeing impact as gracefully as my 20VT. The new barrel with brake seems to have about the same minimal muzzle rise as the VT so I am extremely happy about that.
Today I shot 14 three shot groups with various combinations of charges and seating depths with 32 Gn Vmax, 40 Gn Vmax and 39 Gn Sierra's. Several of the groups were in the low 2's and a couple in the high 1's. Four groups loaded with 40gn VMax were touching the lands and averaged a cumulative .211" CTC. Those 4 groups varied between 22.2 and 22.8 grains of 4198 with CCI 450 primers. Velocity of those 4 groups ranged from 3684 and 3856 FPS respectively. Several of the groups had the bullet seated away from the lands (.003 to .006) which the gun did not like. Despite that, the 14 groups cumulative average group size was.302" CTC total. I have never loaded 32gn in a 20P before. My first group of 3 32's was 24.5 grains of 4198 and produced a sizzling average of 4326 FPS with a SD of 9 FPS. I thought my Magneto Speed Chrono had to be giving false readings. I had built up several layer of aluminum tape onto the recessed area of the bayonet to prevent it getting burnt by the muzzle brake and thought maybe that was affecting the chrono's accuracy. Another thought was my barrel is 1.08" OD and the Mageneto speed literature says it is designed for up to 1" barrel. The literature states large barrels can affect accuracy of readings due to the increased distance from bullet to sensors. I did not see any signs of pressure so I shot the next 3 which seemed ok. I shot a total of four, 3 shot loads with the 32V ranging from 24.5 grains to 25.4 grains; the last three shots averaging 4434 FPS. Holy COW! I violated some basic reloading principles and learned a valuable lesson. I did not notice the primers were starting to protrude a bit on the last three rounds and on the very last shot of the final 12 rounds the primer popped out. I obviously need to be more vigilant when playing in uncharted territory. Thankfully the bolt head and lugs were not damaged so all's well that ends well. All in all I am thrilled to have another 20 shooting super well and am very pleased with Criterion's work. I have 3 of their 20 cal barrels (Savage Pre Fits) and they all shoot superbly. |
#2
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20 Practical 4443 FPS...oops
I would be very cautious with those loads, they seem to be on the high upper end. Play safe and sane and do not damage your rifle or injure yourself. Bill K
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#3
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20P overload
Those 32's were well beyond upper end.
Interestingly I can not find any signs of pressure on the brass of the first 6 of 12 despite moving at 4326 and 4362 average fps for each 3 shot group. No impressions of extractor/ejector marks when viewed under magnification. Primers tight in their pockets. Easy bolt lift. |
#4
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26 gr. Barnes Varmitt grenades.
I'm going to try some 26's in my soon to be completed 20 Tac. I know the B.C. is very low but what fun with groundhogs with in 250 yards! Will update soon!
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#5
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Had no Luck with the 26gr. bullets in my 20TAC. Could not get them on paper at
any yardage. Barrel is a Pac-Nor, 1 in11 twist, 3 grove, 24 inch. Believe twist was to fast for them. Tried then again after rifle sighted in with 32gr bullets and still could not put them on paper. |
#6
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26 gr. Barnes Varmitt grenades.
V. S. I tried them in my 20 V.T. they clocked about 4010 fps. The 20 Tac. must be way too fast, Oh well it sounded fun. Dave
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#7
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I have worked up loads with the Hornady 24gr. NTX bullets for the 20 vt. They worked out quite well for both accuracy and velocity.
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#8
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The best I could do ACCURATELY was 3950 with a 20P, 25" HV Lilja. This is with 24.3 VV133, BR4, 32Vmax and R-P brass. 44xx is smokin'!
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#9
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26 gr. Barnes Varmitt grenades.
I used 20.3 gr of Rel-7,shot .176" @100 yds. 3 rounds. WSR primers. 1.860 oal. Devastating on ground squirrels & feral cats. Love my .20 V T. Lilja 1/12 twist, Rem 700 action.
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#10
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20 Practical
I will try some 32's at appreciably reduced powder levels...will go for velocity closer to 4150 fps so the brass will live. I expect it will shoot pretty good as even the overloaded rounds gave halfway decent accuracy....two of the four groups were in the 3's and one in the 4's.
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