DCRA 7.62 Conversion Range Report |
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Online Points: 6539 |
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Posted: August 03 2019 at 2:50pm |
A few weeks back I loaded up some 7.62 NATO “Mexican Match” to test out my theory on why the No. 4 7.62 conversions did not shoot well. My theory was wrong. But I did discover something that I’ve not heard before as a possible cause or contributor.
Here are the Loads: 1. Canadian Dominion Arsenal (DA) 1959 Ball (147 Hard Point Boat Tail) military Service issue 2. DA ‘59 above, with 150 gr SMK subbed for the 147 gr ball projectile. 3. DA ‘59 case, CCI #200 Primer, 42.0 gr Varget, pulled 147 gr DA ‘59 ball projectile from 2 above. 4. DA ‘62 case, WLR primer, 40.0 gr Varget, 168 gr SMK as a control (proven match load). I expected load 2 would be best of loads 1 thru 3. It was not. 2 x 10 shot groups of each load off the bench at 200 yards, PH 5C aperture sight. This is a UF56 Mk 2 action with CA 7.62 barrel, mid-band barrel bedded. Here are the targets. Note there was some sight adjustments between groups as noted. Load #1 DA 59 Service Ball, Group 1 - 2.6 MOA extreme spread, not bad for service ammo. Load # 1 DA 59 Service Ball, Group 2 - 6.0 MOA extreme spread, terrible. No idea why second group was so bad. Moved rear sight 1 MOA left before shooting this group. Load # 2 150 gr SMK subbed in for Service bullet, Group 1 - 2.8 MOA, Fair result, expected better Load #2 150 gr SMK subbed in for Service Bullet, Group 2 - 5.1 MOA, terrible, expected way better. Load #3 42.0 gr Varget, 147 gr Pulled Service Bullet, Group 1 - 2.0 MOA much better than expected Note the shift in MPI, about +4 MOA from previous loads which all has the original factory powder charge. Load #3 42.0 gr Varget, 147 gr Pulled Service Bullet, Group 2 - 2.1 MOA much better than expected. Adjusted rear sight 3 MOA down and 1 MOA left before shooting this group. Load #4 40.0 gr Varget, 168 gr SMK Match Load Control Group. Note the 2 shots that were just outside the X ring (10.9) 1.7 MOA Extreme Spread. The group was 1.5 MOA for the first 9 shots. Conclusions: Poor accuracy of 7.62 Service Ball Ammo was not related to bullet quality. The two 10 shot groups with pulled bullets loaded with 42 gr Varget grouped at approx 2 MOA extreme spread. 150 gr Match bullets loaded in place of the pulled bullet did only slightly better. When loading up these cartridges, I weighed the powder charges of 20 rounds and was surprised it ranged from 40 to 43 grains. The powder appeared similar in stick size to IMR 4895. I returned the individual charges back into the case they were dumped from, so load #2 with the 150 gr SMK evaluated the as charged service ammo with a modern match bullet. Variations in powder charge weights most likely was the cause of poor accuracy. I suspect the service ammunition may be loaded to a higher velocity than Load #3 (42 gr Varget), and the higher velocities/pressures may be flexing the action more than the .303 and giving erratic groups. I intend on doing two more tests: 1. Pull service bullets, dump powder into powder measure, recharge cases with 40.0 gr of service powder, reseat pulled service bullet. 2. 42.0 gr Varget with 150 gr SMK. |
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Online Points: 6539 |
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I may have posted this before, but likely lost in the “Enfield Rifles” forum. I shot this target last year, prone in sling, no support, PH 5C aperture sight. UF56 No. 4 Mk 2 DCRA (Canadian Arsenal Ltd, Long Branch 7.62 service weight barrel).
Load: Dominion Arsenal (DA) 1962 7.62 NATO Case Neck Sized WLR Primer 40.0 gr Varget 168 gr Sierra MatchKing 2.80 inch OAL 200 Yards on NRA SR Target. Score is 100-8x. This is the most accurate Lee Enfield I have. |
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Canuck
Special Member Donating Member Joined: January 17 2012 Location: Agassiz BC Status: Offline Points: 3535 |
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Very impressive! Thanks for sharing your results.
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Castles made of sand slip into the sea.....eventually
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Sgtrick
Groupie Joined: April 28 2020 Location: Saskatoon Sask. Status: Offline Points: 29 |
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Very nice target. Well done.
Im just starting to work with my 7.62 longbranch, conversion number 54. I have a bunch of 1961 DA ball ammo that I want to try but am really interested in shooting powder coated cast bullets. Thanks for sharing this.
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Online Points: 6539 |
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Sgtrick, i have DA 59, 60 and 62 ball ammo. I don’t think I have any 61. I’ve shot a few hundred rounds of this ammo, accuracy is 3 to 4 MOA, sometimes a bit better.
I ran a test a few years back where I pulled the bullets on 40 rounds and re-metered the powder charge. These were all from the same lot of DA ‘60 ball ammo. I found that there was a vary large variation in the powder charge weight (as much as 2 grains) which was causing vertical stringing of the groups. With a consistent powder charge (+/- 0.1 gr), the groups tightened right up. I had first suspected poor quality bullets, but that was not the reason for the mediocre accuracy of the service ammo. I posted the results of this test on the Enfield Rifles or Reloading forum (can’t remember which). I’ll see if I can find that post and ask our administrator to move it over to the 7.62 Enfield forum. I’ve not tried cast bullets yet in any of my Enfields. What is very appealing with shooting cast is that it is very easy on the action and barrel. The much lower pressures and much less erosion of the throat and wear of the bore. I suspect the barrel life with shooting cast is in the tens of thousands of rounds. |
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Pukka Bundook
Senior Member Joined: February 02 2015 Location: Canada Status: Offline Points: 1369 |
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Very good info to have on those powder variations Geoff.
I would not have expected such a wide spread! That is a Very pretty target! BTW, I haven't noticed Englishman.ca posting; Is he OK do you blokes know? Maybe I just missed seeing his posts...
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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He's not listed as being logged on since August of last year! Does anyone have a direct contact with him?
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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Pukka Bundook
Senior Member Joined: February 02 2015 Location: Canada Status: Offline Points: 1369 |
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Just sent him an email, Sham.
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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Thanks.
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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Sgtrick
Groupie Joined: April 28 2020 Location: Saskatoon Sask. Status: Offline Points: 29 |
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Britrifles. I pulled the bullets on a couple of 1961 DA rnds to what powder was used. The charge was about 42 gns of what appears to be 4895. I plan on loading some 4895 loads and crono them and compare with the military loads. I might do what you did and pull bunch and weight the charges.
Been shooting powder coated bullets in my 303s for a few years now for the reasons you mentioned. Easier on these fine old rifles.
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Online Points: 6539 |
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Thanks Richard. I totally pulled that last shot off to the left, I knew I had done that when the shot broke. Kinda ruined the target. I was proud of how tight the elevation spread was (1/2 MOA), the barrel just sings with this load.
One of these days, I’m going to go into serious prone shooting mode with the DCRA conversion and see if I can break the 100-10x barrier that seems to have eluded me so far. I’ve done it off the bench, but to me, that “doesn’t count”.
I hope Englishman is OK. We have not heard from him in a while. |
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A square 10
Special Member Donating Member Joined: December 12 2006 Location: MN , USA Status: Offline Points: 14452 |
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me too , i had not realized how long it has been , hate when this happens
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Pukka Bundook
Senior Member Joined: February 02 2015 Location: Canada Status: Offline Points: 1369 |
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Gents,
My email to Simon, (Englishman) came back undeliverable. Must be a year since we wrote... Maybe he has changed his email? Anyone have a newer one for him?
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Goosic
Senior Member Joined: September 12 2017 Location: Phoenix Arizona Status: Offline Points: 8792 |
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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Sorry, no. All my contacts are through the forum here. I have access to an IP checker & his "box" still seems to be active at the same location as when he registered.
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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A square 10
Special Member Donating Member Joined: December 12 2006 Location: MN , USA Status: Offline Points: 14452 |
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this happened to me back about 15 years ago - i knew him in a previous life , pre- this enfield site , might be having issues with his computer/service , hopefully we will regain contact ,
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