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- Last updated: 29/11/2016
We all know how popular the PPC cartridge has been to Benchrest shooters, although newer designs are now shining through. It is partly due to the fact that Dr Palmisano and Ferris Pindell designed a superb efficient cartridge shape from the off (Palmisano Pindell Cartridge, PPC). Some designs just work much like a well tuned race engine. It’s a blend of internal and external design, where the harmonics and thermal dynamics of the powder burning cycle just synergise to their maximum thus producing super efficient, clean and un-turbulent and consistent propulsion.
It’s not by chance that the original 6mm PPC case has been expanded, necked down and modified since its design. I run a nice Venom .17 PPC and at the other end of the Spectrum is the improved 6mm Dasher, I have even seen 30 cal versions. But like the original 6mm the .20 PPC is a real honey and specifically designed for the varmint hunting market but also doubles as a great benchrester as well.
I have said this before but think about those tiny .20 cal bullets as they fill a very efficient void between the .17 and .22 centrefire, in fact .172” and .224” calibres is some 0.052 thousandths of an inch which in ballistic terms is huge. That’s like having a 0.243 and 0.308 with no 0.257, 0.264, 0.277 and 0.284” between them, and where would we be without the 25-06, 6.5x55mm, .270 Win or any of the 7mms?
The 20 PPC and 20 PPC Pup are a classic varmint rounds. The case is based on a modified .220 Russian and is transformed when necked down to .20” and is super efficient and uses less powder than larger .20s to achieve the same velocity. This means less fouling and barrel erosion. A .20 PPC in a 24”+ barrels launches a 40-grain Blitz King at 4000 fps whilst using 28-grains of VIT N 133 powder, a 1 in 11 rifiing twist is best although a 1 in 9 would be superb for the larger 50-grain Berger bullets for extreme range Varminting. A 32-grain V-MAX can be pushed to 4300 fps with only 27.5 grains of H 4198 powder. The .20 PPC Pup is just a shortened 20 PPC for use in Benchrest matches but also makes a great vermin/fox load.
At first only Hornady offered a 33-grain V-MAX projectile and Berger a 36-grain hollow point. This was enough to wet the appetite of small calibre shooters worldwide, me included. From this we have four main manufacturers as well as several small, independent makers.
Hornady offer a 32 and 40-grain V-MAX bullet designed to expand rapidly on the target yet deliver superb accuracy at long distances. The 32-grainer has a BC of 0.210 whilst the 40 a BC of 0.275 making them great varmint pills. There is also a 45-grain Soft Point which is good for foxes and has a BC of 0.245. There are also a 24-grain, non-lead NTX and a new Z-MAX 32-grain varmint I have not seen yet!
This is also true of the Sierra Blitz King range, again a 32 @ BC 0.221 was chosen as the lowest weight and at the top end a 39-grainer @ BC 0.287 offers great accuracy long range potential and terminal ballistics.
Berger, synonymous with Match-grade bullets, had a great range of .204s but has reduced them sadly. They now have a 35 and 40 -grain Match Grade fiat base and boat tail Varmints @ BC 0.176 and 0.225 accordingly. The highest BC @ 0.381 is a 55-grain Match Grade Long Range BT Varmint, which requires a fast twist rifiing for stability. Nosler joined the 20 club late but now produces two offerings from their Ballistic Tip range, 32 and 40-grains @ BC 0.206 and 0.239 respectively.
It`s nice to have a custom rifie build but let`s face it, they can be very costly so there is no reason a suitable donor cannot be sourced for the purpose. Only problem is the PPC case head is 0.441” so sitting between .223/0.378” and .308/0.473”. Therefore a PPC bolt or some modification needs to be done by your gunsmith, not a big problem but needs to be done and also if the rifie is to be a repeater then feeding a boxy shaped PPC can also be problematic.
As luck would have it a Sako 75 in 22 PPC turned up and was the perfect donor rifie. The barrel was shot out so a new tube was all that was needed to get the project under way. A Shilen Select Match grade barrel was chosen and supplied in a number 17 profile which translates to Rem Varmint profile. Rifiing choice is key to stabilising those .20 cal bullets. 1 In 11 or 12 are good for the lighter bullets of 30-45 grains but if you want to use the heavier 50 or 55s you need a 1 in 9 twist rate.
I opted for a 1 in 12 as the 39-grain Sierra Blitz Kings were my choice and I wanted to push them as fast as possible without over pressure or stress. A half inch UNF thread was also cut to the muzzle.
Chambering options are plenty for the 20 PPC dependent on the bullet and thus throating needed. You can go neck turned dimensions or not. I like a tight throat myself, so went for a .228” neck dimension on the reamer so a loaded round would have 226-227 thou diameter with bullet for a 1.0 or 0.5 thou per side clearance on firing. Tight but concentric which is why you go the neck turning route in the first place.
A set of Wilson 20 PPC or 22 PPC neck dies can be used and a bush of 0.225” was used for a neck tension of 2 thou. The seater die was a 22PPC with a 20 cal stem fitted and manual set for bullet depth although a calibrated replacement head can be ordered if necessary. Cases are virgin Lapua .220 Russian brass necked down to .204 cal with a series of nitride bushes and there is then a neck turn with a K&M turner for a close chamber to neck fit.
As the Sako 75 was a heavy barrel varmint version anyway the barrel was still free fioating and so all that was needed was to fit a moddy. A new, stainless steel, MAE 38mm muzzle can was fitted because I liked its look, reliability and superb noise reduction.
A muzzle can was also used because the most important part was that the rifie was to be used for foxing and lamping so had to be short. Therefore a barrel length of 19” was settled on. Yes that is short but a quick run through Quickload ballistics (custom case design by me) program and you will find how efficient the 20 PPC is. Overall length of the rifie with sound moderator fitted is a very handy 44” (See Table).
It never ceases to amaze me how efficient some cases are even if you do cut the hell out of a barrel. Those velocities are from the 19” tube further proving how good that PPC case is.
This rifie really liked the 39-grain Sierra Blitz Kings that shot bug hole sized groups from the off. A load of only 28-grains of Vit N135 under this bullet with a COL (cartridge overall length) of 52.14mm achieved 3885 fps/1307 ft/lbs energy. Largest group was 0.5”, smallest was five through the same hole! Proving that sometimes you do not have to go the full custom rifie route and you can save yourself a lot of cash with a very good match-grade barrel on a standard action like this Sako 75.
Fitted with a NightForce NXS scope and zeroed at 100 yards the Quick Target ballistics program was used to generate some down range performance for the 20 PPC/ BlitzKing load with be -0.9” low @ 200 yds, -5.6” at 300, -15” at 400 and -31” at 500. That’s a great set of ballistic results and makes for a very good fox or long range varmint load in my book. Fitted with a MAE moderator the muzzle report from 28-grains powder is like a sparrow’s cough and you can spot every shot as there is zero muzzle lift.