i guarantee that NO ONE has tested max pressure of a mini action besides the factory. ONCE AGAIN, we DO NOT recommend pushing the limits of any cartridge beyond what is SAAMI spec. To retain the warranty, factory ammunition must be used. I cannot tell you how many instances we have had with people and their hand loads. Be safe, as noted by Bluntforcetrauma, what do you really gain by the added pressure?
Howa mini-action in grendel to be released in mid-2016
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Ahh... I'm OK with getting 3 loadings out of my brass..if it gives me the performance I want.
I have no way to test the pressure of my handloads. With my CZ527 and the Grendel, when I start backing out primers, I call that the max loads then I back down .2 gr . I figured out a long time ago that it was a dumb idea to publish those loads here. Still and all, we ought to get better velocity out of a bolt action than a AR.
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Basis? How about a few years of shooting Lapua 6.5 Grendel brass in a bolt action (NOT a Howa Mini as they are not yet available). When I got my Grendel I tried a number of different loadings, some of them well over the design pressure. I didn't pop primers, but I have a dozen cases on their fourth reload that don't hold a primer any more. These cases are now givaways to collectors or Grendel fanciers who want a dummy case for reference.
My frustration is down to repeatedly stating that the brass is the limiting factor and yet y'all keep running down the 'we need a bigger action' route. If you want the higher velocities, get a bigger case.
You have made some assumptions that since the Grendel is derived from the PPC and that from the 220 then 7.62x39 that the Grendel brass is built the same as the 6mm PPC case. I have owned rifles in both cartridges and whilst the exterior dimensions of the head are the same, the internal construction isn't. The head also appears to be softer than the Lapua high pressure brass (220 Russian, 6mm BR, 6.5x47 Lapua and 6.5x284).
I don't pretend to know what the Grendel brass was originally specced for, but I suspect that it was designed for the target rifle - the AR15. The SSAMI specification appears to be 52k PSI (average) which makes 60K PSI a significant overload. A pressure rating of 52k PSI will work nicely in a 50k PSI action such as that found in the AR15. Stoke it to 60k PSI in an AR15 and the action will let go, but in a (good) boltgun like the Howa Mini the action will work well (their design failure is possibly in the 70 to 80k PSI range like most bolt actions) however the brass becomes the weak link in the system as it will still stretch and fail quickly with repeated loadings.
My hunting load is a 100gn NBT or TTSX over 31.5gn of BM 8208 (IMR 8208XBR in the USA) which delivers 2980fps out of the 21in barrel of my Zastava m85 based rifle. It is probably quite warm, dancing at the 55k to 58k range (sadly we have noted before that Quickload does not seem to model the Grendel very well at all) but is all-year capable (temperatures range from -5 to 35 deg C). I note that the Hodgdon load data for the same load is maximum at 30.8gn and 2730fps from a 24in barrel at 47,600psi, some on this forum have gone further in their AR15s, and others have noted bolt failures too.
As LRRP has noted, don't chase velocity. Chase accuracy and let the bullet BC do the job - even the 100gn bullets really do work well.
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IIRC as I was researching hand loads for my Grendel bolt, 58k psi was the number I ran across as max for the brass.
When I did my workup with Hornady 129 Interbonds (see https://www.dropbox.com/s/45bfe3ki85...0worksheet.pdf), I closely monitored brass, primers and velocity as I exceeded Grendel AR max with CFE 223.
I've pondered using Federal GM small rifle primers versus CCI 450 small rifle magnum primers. What do y'all reckon the difference would be?
Edit: Chronograph used was Chrony Beta Master; AA brass was Lapua.Last edited by BjornF16; 01-06-2016, 01:02 AM.LIFE member: NRA, TSRA, SAF, GOA
Defend the Constitution and our 2A Rights!
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I found that changing to a federal 205 SRP from a Win SRP closed up my groups as per pic.
The load was 31.5 gn CFE-223 Hornady brass 123gn SST @ 2.280
Both loads are the same apart from the primer, I repeated this a few times to be sure.
It was in a Savage Grendel LBC .264 20.5" Barrel with suppressor.
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Originally posted by Doon View PostI found that changing to a federal 205 SRP from a Win SRP closed up my groups as per pic.
The load was 31.5 gn CFE-223 Hornady brass 123gn SST @ 2.280
Both loads are the same apart from the primer, I repeated this a few times to be sure.
It was in a Savage Grendel LBC .264 20.5" Barrel with suppressor.LIFE member: NRA, TSRA, SAF, GOA
Defend the Constitution and our 2A Rights!
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Bill Alexander texted back with some info. I quote:
"Draw and heading dies are .220 Russian. Only the final draw, necking, and taper dies are different."
"Case has been tested to run safely at 58,000 psi and can be reloaded. Proof loads run at +67,000 psi."
"All the margins from the SAAMI max are to provide safety."
"Howa's action is adequate for the SAAMI spec, but this is not a full-blown benchrest rig. It will come unglued if pushed.":: 6.5 GRENDEL Deer and Targets :: 6mmARC Targets and Varmints and Deer :: 22 ARC Varmints and Targets
:: I Drank the Water :: Revelation 21:6 ::
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Originally posted by BluntForceTrauma View PostBill Alexander:
"Case has been tested to run safely at 58,000 psi and can be reloaded.
"Howa's action is adequate for the SAAMI spec, but this is not a full-blown benchrest rig. It will come unglued if pushed."LIFE member: NRA, TSRA, SAF, GOA
Defend the Constitution and our 2A Rights!
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Originally posted by BluntForceTrauma View PostBill Alexander texted back with some info. I quote:
"Draw and heading dies are .220 Russian. Only the final draw, necking, and taper dies are different."
"Case has been tested to run safely at 58,000 psi and can be reloaded. Proof loads run at +67,000 psi."
"All the margins from the SAAMI max are to provide safety."
"Howa's action is adequate for the SAAMI spec, but this is not a full-blown benchrest rig. It will come unglued if pushed."NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com
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Originally posted by usmcm16a2 View PostMy local FFL spoke with LSI today, and my HWA60603 is on order:: 6.5 GRENDEL Deer and Targets :: 6mmARC Targets and Varmints and Deer :: 22 ARC Varmints and Targets
:: I Drank the Water :: Revelation 21:6 ::
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Originally posted by LRRPF52 View PostAnother thing with bolt guns is that if you experience a lug failure, you get to eat a bolt through your face, which can and has been fatal. With the AR15, the blast goes down the mag well most of the time, unless you're really brave/stupid, and you fragment your bolt carrier and upper receiver outwards.
2 locking lugs
3 pressure vent holes in the bolt body
forged one-peice bolt and handle (not brazed on or welded like some companies)
bolt handle itself acts as a third locking lug when closed.
m16 style external extractor and internal plunger ejector.
the receivers are also forged one piece flat bottom receiver with an integral recoil lug. these things are over built in comparison to some other bolt gun offerings.Last edited by Matt @ LSI; 01-06-2016, 09:52 PM.
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Originally posted by Matt @ LSI View Postso a few features about the Howa bolt.
2 locking lugs
3 pressure vent holes in the bolt body
forged one-peice bolt and handle (not brazed on or welded like some companies)
bolt handle itself acts as a third locking lug when closed.
m16 style external extractor and internal plunger ejector.
the receivers are also forged one piece flat bottom receiver with an integral recoil lug. these things are over built in comparison to some other bolt gun offerings.NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com
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Matt @ LSI,
Welcome and hope you stay permanent. Y'all are on a long and profitable path with a mainstream 6.5G bolt gun. Just get them out in hands of shooters and the sales will speak for themselves that an extensive aftermarket product line is necessary. 2 items that should be marketed first, quality replacement stocks and a scope mounting system that will work with the Mini Action and different eye relief distance scopes. IMO
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