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Righto I have decided to rebarrel my t3 7mm Mag to 7 Saum
I will use a DPT suppressor on the sharp end of things and I have 150 plus AMax which went very well in the 7RM when seated out - not so good when seated mag length. I have been using N560 getting pretty good velocity out of the 7RM, also have appx 500gn of 2217.
I keen to hear peoples thoughts on barrel length and twist rate for the 7 Saum for suppressed light rifle.
Cheers
AMax
20-24 inch
The one i’m putting together will be 20”.
mines 22 from action face. 162 amax 2217 65.7 gr at coal of 2.184" getting 2953fps
No shorter than 20" I would say
I’d go with 22in, but not shorter than 20in. What’s the twist rate of your 7mm RM barrel ? 1:8 or 8.5 would be best if you want to run bigger high bc pills
22" :)
20" just short of 3000fps with 168 Berger
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I'd atleast run a 9 twist but ideally I'd run and 8 twist as it's more versatile. I hate long rifles so I'd be running the 18 if I had a suppressor but then again I'd probably just run an unsupressed 20-22inch barrel for weight and performance bonuses
19 inch barrel 2900 168 berger
Just chop your remmag to 20" and your away
EDIT .......2.814"CoalQuote:
Originally Posted by robhughes-games
My suppressed Mod 7 has a 18" barrel, so a bit more handy in the bush. 160's @ 2725 mag fit, so fair loss from the 2950 mag fit when it was 22". As 199p said above, why not just cut your rem mag back to 20"?
Cheers
Thanks All
A T3 RM has a 1:9.5 twist.
I think I will go with 1:8 or 8.5
Re chopping the RM barrel back to 20" - for me the issue is that the rifle shoots very well when the projectiles are seated out, but does not go anywhere as well when projectiles are seated to fir the mag. I realise that it is possible to play around with the plastic mag to gain a little extra space, however I imported a billet magazine so keen then have rounds all fit into this magazine.
And then of course there is the fun doing something I have never done before i.e. a rebarrel :)
Cheers
AMac
You will need to play around with different pills if you want to find one that shoots well from Mag length seating COL. And you need to advise your gunsmith what pills you intend running so he can chamber to suit. You’re probably better off running two different pills and loads, one mag length for the Bush and one seated long to maximise case capacity and bullet choice and performance and single feed
If you trim the plastic tip back with a meplat trimmer to about 1/2 length you can gain about 80-100 thou seating depth easy enough with out appreciable loss in BC or performance
In the end I went with 20" at 1:9 - which True Flite recommended and the digging around I did seems to indicate it will be ok for the 175Gr ELD-X and 180s. I sentAttachment 163834 this dummy round with the 175 EDL-X COL of 3.080" I have 2217 to start with and magnum primers and was hoping I might get suggestions for loads please?
Will your eldx be going fast enough for good kill performance at range? I run the 178gr eldm in 30cal at 2920fps
Should be heaps I ran the 225 eld m at 2400 and was plenty at 400. I actually prefer to keep the elds a little slower if possible.Quote:
Originally Posted by Smiddy
How far do you plan on shooting deer at? A 162/168gr goes pretty well a fair way out there. I'm still using the old 162gr Amax in my 22" 7mm SAUM, it seems to kill pretty well at extended ranges.
Here's one I shot on Friday night from 659 yards, only a little red, hence the base of neck shot to save as much meat as possible.
https://www.youtube.com/watch?v=lMUt2Ju6UMk
Nice shot GWH and a really well put together video.
I will keep things to a max of 500m as I just don't have the opportunity for practicing longer shots now work has taken me to Auckland. My longest shot with the 7 mag was 465m - lived in Wellington then and got to shoot at Trentham to 600 and that went pleasingly well.
Attachment 167009Attachment 167010
These photo's are not the best but I got my T3 rebarrel back this week and here she is :)
7mm Saum 20" Trueflite ultra match, fluted 1:9 twist
Senator carbon stock
Zeiss HD5 3-14x42 with target turrets
Mountain tactical 3 shot mag.
Tally light wright rings
SS recoil lug, trigger spring replaced, half cock.
3.4 kgs with the DTP magnum suppressor.
I hope like XXXX it shoots after the spend
Really happy with weight and balance this rifle should see me right for the rest of my days !
Any advice re 168-175 grain loads with AR2217 welcomeAttachment 167012
162 amax cci mag primer 65.7gr 2217 coal of 2.814" @2952fps
My experience with SAUM and 160 - 162 gn pills and RL23, N560, Hyb100V and 2217 is that you start hitting pressure signs around 60.5 - 61 gn. Every bbl is different but for 168-175 pills I’d be starting at 57gn and work up carefully
Thanks chainsaw and rob hughes - Trueflite have chambered for a 3.080" coal so it will be interesting to see if seating the projectiles out has a beneficial effect.Quote:
Originally Posted by chainsaw
Correction to above, checked my log book & 2217 with 162 AMAX was 65.5 - 66gn.
When i ran 2217 with 162 Amax's i was at 67.5gr. Its right on the edge. Just over 3k from my 22" barrel and shot bloody well. Was a compressed load and was always a pain. So ive switched to RE26 which gives more velocity, lower pressure and below 100% case fill.
Thanks guys.
ADI have starting loads with 2217 at 61gr max of 65.5 gr compressed for a 175 pill, GWH is sounds like RE26 might be a good option if/when I can get some - for now its making do with 2217.
I have some very old 2213C and not so old N560 - I was wondering given the short 20" barrel whether there is a benefit to be had velocity wise from faster powders than 2217. Might post this question on the reloading sub forum.
The N560 would be worth looking into.
2213sc I found super slow
Ive found you can get faster velocities with heavy for cal bullets even in shorter barrels with slow burning powders.
Couple of trips to the range now and am pretty pleased to see some good results accuracy wise - velocity not where I had hoped but heck 165 gr TGK – 4 loads 4 groups averaged 0.55moa. Best accuracy with 175 Eld-x @ 2,600fps and 2,850 for the 165 gr TGK.
Into the Lewis Pass for a few days Thursday morning to hopefully try the new set up for real !
Attachment 169125
That's looking pretty good. How many grains if 2217(the special mix) are you using with the 165?
Accuracy with weight trumps pure velocity most of the time. It's mainly about wind judgement.
66gr of 2217 - my "special mix" is N560 have not tried that yet....Quote:
Originally Posted by Gkp
Good stuff! I haven't used either of those pills, let us know how they go
