Don't light a match Gibo
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So if what you say is correct then recoil would increase at a linear rate with projectile weight if the powder charge stayed the same. However taking what Tussock has said about the different 'reactions', if the pressure/ heat/ vibration also increases then the recoil thrust may not actually increase as much as might be expected because the energy loss also increases ….
Can we have our cake and eat it too - a low recoiling but high performance superlight mountain rifle ??
Im not sure where this convo is going or how it relates but I can shoot .260rem 6.5x47 Lap and 6.5 Creedmoor in this same chassis, if any of you can feel a difference in recoil you are doing better than me. All are light recoiling "kid friendly" cartridges. If you are scared of a little recoil its probably best you forget about hunting and take up cycling
is a SIMILAR weight/shape projectile at a SIMILAR speed with somewhere around 15-20 grns LESS powder than another often slighted cartridge that is often said "to boot like a mule".....
Recoil energy formulae typically attribute an average of 4700 ft/sec (or similar) departure speed to the mass of gas escaping behind the bullet treated as a point mass of the same weight as the starting powder charge leaving in the same direction as the bullet. Sum the momentum of the bullet and powder, apply conservation of momentum using the rifle weight, and then calculate the recoil energy from the resulting rearward velocity of the rifle.
For a given weight of rifle and barrel length within a single calibre, bullet energy plotted against rifle recoil energy follows an efficiency curve for different cases and bullet weights. More efficient cases may move their data points somewhat above the average, and the converse is also true. The same applies to the suitability of powder in its ability to transfer energy to the bullet. But where a shooter chooses to operate on this curve depends more on where it is felt the optimal trade-off exists between bullet energy and rifle recoil. Tussock has identified what he considers to be the sweet spot on this curve for 6.5mm (probably also factoring in the ability of this calibre & bullet weight to kill red deer sized critters at normal hunting ranges), and it is a 140gr bullet in a 6.5x47 with a suitable powder - and I'm inclined to agree with him.
Wingman, please tell me a bit about your reamer: your freebore length and neck diameter (clearance) choice and perhaps your thinking that led to these dimensions? I think I would be right in saying that these are likely to be the two variables with everything else staying much the same at standard CIP - unless you also requested the leade angle be tweaked?
Was @gimp original 6.5x47L done with this reamer?
6.5x47L aka the 6.5 creed-before
@outdoorlad are you running your 6.5x47L on an M mag on that nice Tikka of yours? Any OAL issues if so?
The rifle is predominantly a hunting rifle so this school of thought was always foremost on the build specs. Tight neck reamers and long freebores with crazy lead angles for secant or hybrid ogive bullets would limit the range of suitable hunting bullets and adds possible mechanical complications in the field which I wanted to avoid.
The reamer was ground to cut a .298" neck, my loaded non neck turned neck measures .290" and the free bore length set up for the 139gr Scenar at .235". This puts that bullet in 100% neck to bearing surface contact with 5 though jump and a 2.73" COAL.
The lead angle is std CIP.
The 130gr TMK is very much the same dimensions as the 139gr scenar with the same boat tail and ogive shape, other than the plastic tip they almost measure identical which has made for easy tuning of that load.
I look forward to testing some other bullets but early signs show its really not that fussy to load for.
Should try the 6.5x48! its awesome!!!
The internet says yes.
https://www.nzhuntingandshooting.co....eedmoor-44462/
I knew it, a 260 is waaay better.
Sent from my iPhone using Tapatalk
Correction, after studying the badly photocopied paperwork closer it is a .293" neck and .135" Free bore
@Mathias yes a M magazine, no problems, although I haven’t tried the 143/7 ELD’s in it.
The 140amax was fine.
I just found an old thread from 2012 which had 5x groups from someone 6.5x47L. Compared to my old one, or the one in this thread, it shot like a bag of arse. No better than a good factory rifle. The groups mine shot would fit between the holes in the paper from his. This may explain why he sees them as a waste of time.
Spent this evening loading up some test rounds finally. Nothing to scientific, just a full case of RL16 which is 41.5gr to the bottom of the neck. A small crunch on the longer 143gr eldx but no real compression or seating rebound. No pressure even on the heavier bullets with this full case charge so its the case volume that restricts any further velocity with RL16 however it still leaves the max charge of 42gr of 2209 velocity in its dust.
This test is more a max speed test on each brand and weight and will test the extreme spreads. I'll run them over the chrono and put them on paper in the next couple of days.
The projectiles to test are:
130gr Hornady ELDM
136gr Lapua Scenar L
130gr Sierra Tipped match king
139gr Lapua Scenar
143gr Hornady ELDX
130gr Berger VLD Hunter
123gr Lapua Scenar
123gr Hornady A-Max
Attachment 106995
Nice one Wingman - show us what the RL16 can do! Any chance of also reporting the CoL with each please so we have all the necessaries for QuickLOAD comparisons?
Sure I will list this for you here too. Thanks for the email too, Ive been meaning to return one but work has been crazy this week.
Forgot to mention, the 123gr lapua and A-max's are loaded with 39.8gr of 2208 (varget) not RL16. This is the max charge in my rifle for the 123gr bullets.
I have already run tests with RL16 behind the 123gr bullets and the average velocity from 5 shots with 41.5gr (same load as above-full case) was 2954fps for the A-max and 2948fps with the Scenars. 40gr of 2208 gives approx 3030fps but was showing light pressure.
I have also tested BM 8208 with the 123gr bullets, my max load of 36.5gr gives me an av of 2910fps with Scenars and 2938fps wit Amax's.
36.0gr of BM 8208 behind the 130gr TMK gave 2818fps.
Will be shot from my 24" long Trueflite 1-8" twist. All primed with CCI BR-4s and neck sized twice fired brass.
All seated approx 10 thou off lands.
COAL's as follows:
130gr Hornady ELDM 2.755"
136gr Lapua Scenar L 2.740"
130gr Sierra TMK 2.775"
139gr Lapua Scenar 2.685"
143gr Hornady ELDX 2.780"
130gr Berger VLD Hunter 2.690"
123gr Lapua Scenar 2.720"
123gr Hornady A-Max 2.725"
Results; shot prone off front and rear sand bags without any breaks. Barrel got hot but not so hot you couldn't hold your hand on it. Shot in the order of this list:
Cold bore but not cleaned.
123gr Hornady A-Max
Velocities FPS: 2988, 2996, 3007, 3012, 2997 ES: 24 fps
https://i.ibb.co/ZMfL2R1/20190311-162721.jpg
130gr Sierra TMK
Velocities FPS: 2909, 2899, 2899, 2898, 2896 ES: 13 fps (group was .447")
https://i.ibb.co/SXdBpdf/20190311-162537.jpg
130gr Hornady ELDM
Velocities FPS: 2893, 2888, 2890, 2891, 2892 ES: 5 fps
https://i.ibb.co/52gZMJ2/20190311-163845.jpg
139gr Lapua Scenar
Velocities FPS: 2858, 2861, 2850, 2852, 2853 ES: 11 fps
https://i.ibb.co/44DpWcB/20190311-164146.jpg
136gr Lapua Scenar L
Velocities FPS: 2904, 2898, 2891, 2898, 2899 ES: 13 fps
https://i.ibb.co/y6W0P1Q/20190311-163141.jpg
143gr Hornady ELDX
Velocities FPS: 2855, 2878, 2835, 2832, 2848 ES: 76 fps
Remember this load was lightly compressed due to the longer bullet, this is typical of a compressed load of RL16, the ES jumps and the groups open up. This barrel has shot half inch groups with the ELDX with 39.5gr of RL16 at 2780fps.
https://i.ibb.co/7XMbgH5/20190311-163647.jpg
130gr Berger VLD Hunter
Velocities FPS: 2904, 2909, 2904, 2900, 2906 ES: 9fps
https://i.ibb.co/t2fgMVq/20190311-163352.jpg
123gr Lapua Scenar
Velocities FPS: 3001, 3008, 2993, 3002, 3003 ES: 15 fps
https://i.ibb.co/PCfK3gg/20190311-162851.jpg
So the groups were nothing fantastic but that was expected with a full case, the RL16 seems too like a bit of room to move. the TMKs and VLDs both did ok and this has in fact been my hunting load. Id be willing to bet most groups could shrink up to half that with .5gr to 1gr less powder. It has not been a fussy barrel which give plenty of options but I am seeing a preferred weight of 130gr with the RL16 with 40.5gr to 41.5gr performing really well.
I should probably get a bunch of other 140gr bullets to test too, they seem to sit best around the 2800-2850fps mark in this barrel.
The 130 gr Berger vld hunter and target and the 130 gr hornady are what shoot best in my 1 in 8.5" 6.5 creedmoor. But I reload with 2209. I ll ave to try the Reloader 16 at some point.
@Friwi I have a couple of Creedmoor barrels to drop off for fluting when finish machining them so will drop in some RL16 for you to try.
Sweet.Thanks.