Roe
Introduction
Most factory calibres on offer to stalkers today will equally get the job done in the right hands when ensuring correct bullet placement and bullet construction. But sometimes it’s just nice to own something different. I quite fancied creating as an efficient cartridge design that I could, whilst using a quality existing parent case that would be in a deer calibre but could also double as a fox/long range round. Also it was to burn no more than 40-44 grains of powder and provide good velocity from a short 18 inch barrel initially.
18 inches allows a muzzle can to be fitted without increasing the overall length of the rifle, thereby making a highly practical stalking arm or 4x4 fox lamping kit. Calibre choice was settled on as 6.5mm due to my liking for the .260 Rem cartridge and regard for the venerable old 6.5x55.
I had to find a parent case allowing maximum internal powder charge that would burn efficiently and totally within a short barrel but still provide safe pressures and good ballistics. Lapua 6.5x284 brass fitted the bill due to the rebated case design would be perfect when I reformed to a more squat format with highly efficient internal combustion chamber. The difficulty was in the case forming that would need a series of forming dies and final loading and bump dies.
I quickly drew up a reamer print and then sent to it Dave Kiff from Pacific Tool and Gauge in the States to have a barrel chamber reamer made with the correct throat for a 120 grain bullet and ordered a Walther Match grade stainless steel barrel with a varmint custom profile with total length of 18 inches unchambered and 1 in 8 twist rate. It would threaded to fit the switch barrel RPA Quadlite rifle that I use for calibre testing. It proved so efficient I had another barrel chambered the same but with a 28 inch length.
Rationale behind the Rapier
The parent case, the 6.5x284 is 2.160inches long with a 35degree shoulder that burns 49 grains of powder to push a 129 or 130 grain bullet weight at 2850fps and 2327ft/lbs energy from a 24 inch barrel. A mighty fine cartridge in its own right but known for shorter than average barrel life but I wanted to achieve more realistic powder consumption yet still achieve longevity to the barrel and still turn out a cartridge that would send a 120 grain 6.5mm bullet out of that short barrel at 2800fps and develop 2090ft/lbs energy. The case would be only 1.88 inches long but have a more parallel profile and still keep the steep shoulder angles to decrease case stretching yet form a very short boxy internal chamber so that the powder charge could burn cleanly and highly efficiently to achieve maximum ballistic potential.
How is this possible I hear you ask if I intend to shorten the case by 0.28 inches, for the reason stated before , well certain calibres have a finite powder charge that works best within that calibre range, whereas the 6.5x284 is a little “overbored” the Rapier is just about right, well that was the theory.
Case forming
A series of four forming dies are used to gradually reduce the shoulder and neck junction back to its final position whilst reforming the shoulder angle and leaving a long neck for trimming.
The Rapier design utilises a case with a long neck of 0.337 inch not only for bullet support but also to ensure proper powder burning within the case for as long as possible. After Die 3 the case is trimmed to a length of 1.88 inches, the case is then deburred inside and out and then the neck is expanded with a mandrel starting with a 6mm and then a 6.5mm size. The reason being that in the forming process the neck is thickened a lot, and a small donut forms at the base on the neck internally, the 6mm mandrel smoothes out the neck and the 6.5mm size allows a neck turning mandrel to seat nicely.
Neck turning is essential to remove excess neck brass, in this cartridge one side is 24 thou thickness so at least half that needs to be removed to give a good neck tension that I wanted. Because the chamber dimensions of the reamer is 0.2904 I needed to turn the necks to allow a clearance for bullet release of at least 2 thou i.e. a thou a side minimum. I therefore neck turned to 0.287 inch and then when a 120 grain Sierra ProHunter bullet was seated in the case the o/d of the neck was 0.288 inch giving me the minimum requirements.
Die 4 is cut with the finishing reamer and is used as a true up die and a modified 6.5x284 body die ensures it chambers.
Wilson die blanks were re-chambered so that each reload was as consistent and accurate as possible with separate neck bushes.
Field tests
Bullet weights between 85 to 140 grains give a reasonably wide choice for speedy flat shooting fox rounds and superb efficient high ballistic coefficient deer/long range loads.
Due to the relatively small boxy nature of the “burn” chamber and a water charge weight of 50 grains (bullet not seated) meant powders in the medium burn rate would yield the best results.
18 inch Barrel results.
The light Sierra 85 grain bullets have a nice hollow point and I achieved 3167 fps and 1893 ft/lbs with a load of 43 grains of Vit N133 but because of the lack of bearing surface to seat they were a way off the rifling and accuracy was 1.0 inch.
Best lightest bullet was not the Berger 100 grain but the Lapua Scenar 108 gr bullet with a load of 42 grains H4895 achieving 3014 fps and a healthy 2017 ft/lbs. Not the top velocity but best accuracy at 0.45 inches for three shots.
Although the 120gr A-Max was outstanding, there is a 123 grain A-Max but I had none to test. A cracking load of 41.5 grains of Vit N540 spat out that high BC bullet at 2860 fps for 2180 ft/lbs and would genuinely group three shots into less than 0.35 inches at 100 yards.
Substituting the A Max for a Sierra Pro Hunter of 120 grains and 41grs of Vit N540 was a marriage made in heaven, 2866fps and 2189 ft/lbs and 0.5 inch groups. Better still for a deer load was the Hornady SST 129 grain bullet was well balanced at 40 grains of Vit N150 with a good velocity of 2850 fps and sublime accuracy of 0.25-0.35 inch.
140 grain bullets were fine but better in the longer barrel.
28 inch Barrel results
This is for your long range Varminting or just clanging steel silhouettes.
Again the 120 grain A-Max was superb, now a load of 45 grains of RL17 propelled that wind slippery bullet out at 3200 fps dead for 2728 ft/lbs. Accuracy too was very good 0.25-0.45 at 100 yards and still ½ MOA out to 600 yards.
The Lapua 123 gr Scenar too again with RL 17 powder, the Rapier likes this powder, shot 3111 fps/2642 ft/lbs with 44 grains and if anything was more accurate than the A –Max.
Upping the weight to the Lapua 139gr Scenar and shifting to RL 19 powder and 46.75 grains gave solid 0.5 inch groups and 3013 fps.
The Berger 130 grain Match VLD was a surprise it was very accurate at 0.25-0.45 inches at 100 yards and seated way off the lands with 42 grains of Vit N150 powder fro 2929 fps and 2477 ft/lbs.
The Berger 140 grain VLD bullets also were very accurate and the RL17 came up trumps with 2955 fps and 2714 ft/lbs from a meagre 42.5 grains load.
18 inch Barrel (ballistics analysis quickload from JMS ARMS)
Bullet
|
Weight
|
Powder
|
Velocity fps
|
Energy ft/lbs
|
Sierra HP
|
85 gr
|
42gr Vit N133
|
3105fps
|
1819 ft/lbs
|
85gr
|
43gr Vit N133
|
3167 fps
|
1893 ft/lbs
|
|
Berger Match BT
|
100gr
|
43gr RL15
|
2985 fps
|
1979 ft/lbs
|
100gr
|
44gr RL15
|
3054 fps
|
2071 ft/lbs
|
|
Lapua Scenar
|
108gr
|
41gr H4895
|
2944 fps
|
1927 ft/lbs
|
108gr
|
42 gr H4895
|
3014 fps
|
2017 ft/lbs
|
|
108gr
|
42.5gr H4895
|
3048 fps
|
2063 ft/lbs
|
|
Hornady A -Max
|
120gr
|
40gr Vit N540
|
2790 fps
|
2075 ft/lbs
|
120gr
|
41gr Vit N540
|
2831 fps
|
2136 ft/lbs
|
|
120gr
|
41.5gr Vit N540
|
2860 fps
|
2180 ft/lbs
|
|
Sierra Pro
Hunter
|
120gr
|
40gr Vit N540
|
2824 fps
|
2126 ft/lbs
|
120gr
|
41gr Vit N540
|
2866 fps
|
2189 ft/lbs
|
|
Lapua Scenar
|
123gr
|
40gr Vit N540
|
2877 fps
|
2261 ft/lbs
|
123gr
|
41 gr Vit N540
|
2914 fps
|
2320 ft/lbs
|
|
Hornady SST
|
129gr
|
40gr Vit N150
|
2850 fps
|
2327 ft/lbs
|
129gr
|
41.5gr Vit N150
|
2913 fps
|
2431 ft/lbs
|
|
Hornady
Interlock
|
140gr
|
44gr RL19
|
2665fps
|
2208 ft/lbs
|
140gr
|
42gr H 4350
|
2445 fps
|
1859 ft/lbs
|
28 inch Barrel
Bullet
|
Weight
|
Powder
|
Velocity fps
|
Energy ft/lbs
|
Hornady A -Max
|
120gr
|
41gr Vit N140
|
3027 fps
|
2441 ft/lbs
|
120gr
|
44gr RL17
|
3138 fps
|
2624 ft/lbs
|
|
120gr
|
45gr RL17
|
3200 fps
|
2728 ft/lbs
|
|
Lapua Scenar
|
123gr
|
42.5gr RL17
|
3119 fps
|
2489 ft/lbs
|
123gr
|
44gr RL17
|
3111 fps
|
2642 ft/lbs
|
|
Lapua Scenar
|
139gr
|
44gr RL19
|
2842 fps
|
2493 ft/lbs
|
139gr
|
45 gr RL19
|
2904 fps
|
2603 ft/lbs
|
|
139gr
|
46.75gr RL19
|
3013 fps
|
2801 ft/lbs
|
|
Berger Match VLD
|
130gr
|
40 gr Vit N150
|
2817 fps
|
2290 ft/lbs
|
130gr
|
42gr Vit N150
|
2929 fps
|
2477 ft/lbs
|
|
Berger Match VLD
|
140gr
|
41.5gr RL17
|
2898 fps
|
2610 ft/lbs
|
140gr
|
42.5
RL17
|
2955 fps
|
2714 ft/lbs
|
Conclusion
The nearest comparisons are the .260 Remington round or the new 6.5x47 Lapua round or 6.5mm Creedmoor.
As the Rapier shows it gives them all a run for their money
With the lighter bullets the Rapier is a very serious longer range fox or varmint round that achieves great ballistics with minimal powder charge and retained down range performance. Here the 120 grain A –Maxes would be my choice.
The 40 grains Vit N150 with SST`s was a good deer bullet with total lethality and minimal carcass damage whilst achieving good penetration and bullet expansion.
Long range use would be spoilt for choice but the Berger 140 grain VLD`s shot tiny groups at all targets down range.
I was pleased with the results but from a practical point of view I know this is not for every one and a .260 or 6.5x47 Lapua would certainly suffice or even the new 6.5 Creedmoor (shorten .260 case) from Hornady.
Case prep is a serious pain in truth but as am 18 inch it’s a great woodland or hill deer gun and with the longer tube a static long range crow sniper, magic.
The kit ( Reamer, Head Space (go and no go gauge)
Kit (die blanks)
Complete dies for chamber
Cases during each stage of forming
Variety of bullet heads
The results
Label here
Reloading kit
Reloading kit
Targets and tool dimension sheet
Rifle and target results from tests
Rifle and target results from tests
A scenic shot in Scotland
Steel Crow target plate
Steel Target plate
Munjac
Hunting results - 2 healthy foxes fall to the Rapier!
Hunting results - 2 healthy foxes
Bruce Potts
Contacts
Julian 07771 962121 Quickload Ballistics
Email : jmsarmsuk@gmail.com
Article and images by Bruce Potts
Julian 07771 962121 Quickload Ballistics
Email : jmsarmsuk@gmail.com
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