Finally someone understands how to test for accuracy I never understood the 3 or 5 round group I remember back in the 90s when I first got my colt delta elite hbar I grouped it with a 20 round mag full and it would shoot. That rifle killed a lot of ground hogs lol
Initial Review - Sterling Arms International (SAI) R9 Mk1, 9mm PCC
- Thread starter Bartok5
- Start date
It was the Army that taught me to use 5 round groups as the standard measure of a rifle's capability. I have always gone with 5-round groups when using Match ammunition for mostly reasons of economy. Match ammo is pricey, so 5-round groups seem to be the norm for precision rifles. I decided to go with 10-round groups for the R9 testing because I know that many folks prefer 10-round groups and 9mm is reasonably priced. Besides which, SAI was kind enough to provide me with 1000 rounds for my review and testing purposes, so the ammo is currently priced right!
I think that 5 rounds is usually enough to include a flier if outliers are going to occur with a particular batch of ammo. My experience testing 5 versus 10 round groups with 5.56mm ammo has been that the 10 round group usually just depicts double what the 5 round group shows. If there is one flier in a 5 round group there will be 2 or 3 in the 10 round group. And so on.....
Ten round groups do require double the patience and concentration on the part of the firer, as it is easier to make mistakes during an extended firing string. Another reason why many firers prefer a 5 round group.
Three round groups on the other hand, have never made sense to me. The chance of inconsistent ammo (eg. fliers) not showing up in a 3 round group is quite high. For this reason, 5 rounds ought to be considered the minimum, and 10 rounds the ideal if circumstances (eg. cost & time) permit.
Picked mine up Saturday and took it out today sending around 300 rounds through it (150 rnds magtech 115gr FMJ, 100 rnds IVI 124gr. Ball, 50 rnds of Federal 147 gr. Truncated flat point sintered).
Its nice being able to easily thumb rounds into a magazine without resorting to bracing the base of the magazine against a table or using a maglula like as needed with Glock mags.
All rounds fed and functioned fine.
The Mag tech averaged around 1360fps.
IVI was cookin' at around 1480fps.
Federal training ammo wasn't chrono'd.
My only issue with it was that my hammer pin started walking out of the receiver at around the 250 rnd mark.
Switched up the safety with a Triggertech ambi short throw that went in with zero drama.
Changed out the furniture for some B5 Systems stuff and now the hunt is on for a compatible aftermarket trigger.
Its nice being able to easily thumb rounds into a magazine without resorting to bracing the base of the magazine against a table or using a maglula like as needed with Glock mags.
All rounds fed and functioned fine.
The Mag tech averaged around 1360fps.
IVI was cookin' at around 1480fps.
Federal training ammo wasn't chrono'd.
My only issue with it was that my hammer pin started walking out of the receiver at around the 250 rnd mark.
Switched up the safety with a Triggertech ambi short throw that went in with zero drama.
Changed out the furniture for some B5 Systems stuff and now the hunt is on for a compatible aftermarket trigger.
Over the long term, I wonder if Sterling could make a lower that takes Glock mags, as long as its specified they only guarantee reliability with steel Glock mags. Honest Outlaw mentioned that the Staccato HD P4 had no malfunctions with metal Glock mags, but had issues Glock p-mags.
Honest Outlaw said:
Metal Glock mags?!
I have only ever seen one aftermarket company offering metal Glock mags and they were comically expensive but very cool. Not geared up for Canada so between the hassle / expense of riveting them (to stay on the right side of the law and save the world) and importing them I didnt pursue it any further.
Was it these?
https://mbxextreme.com/index.php?page=Glock_Magazines
You may find that the width of the hammer slot in the rear of the Bolt is too narrow for an aftermarket Hammer to reach the Firing Pin. This is why TriggerTech cassettes will not currently function in an R9. You may need to have that slot widened slightly by having a Machinist mill it out to accept the width of a wider Hammer than the R9 comes with.
I measured up a couple of AR hammers and the R9 bolt. The difference is 0.020" to 0.025" depending on the hammer.
It would be a lot less work to narrow the hammer than to widen the slot in the bolt. Narrowing the hammer could be done w a Dremel or even a file, whereas it would require a milling machine to widen the bolt slot. YMMV.
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According to the review, the Staccato comes with Mec-Gar steel Glock magazines. Although I couldn't find a company selling Mec-Gar Glock magazines in Canada, Mec-Gar magazines for other firearms are sold by several forum members, like Marstar and Tenda. They retail on Mec-Gar's American site for $29.99 USD. They would likely approach the price of the bolt-hold-open MP5-ish magazines when pinned, so that would be a wash, but then people could use their plastic Glock mags for non-critical uses like plinking, and still have the option of the more reliable metal magazines for competition or other critical uses.
Your method of narrowing the Hammer ought to work OK, assuming you do not remove too much material resulting in a loss of inertia and light primer strikes. Shouldn't be an issue with soft commercial primers....
The removal of .025" of material across 2/3 of the hammer wouldn't alter the mass that much. There are 9mm hammers that are considerably different and would certainly weigh less.
This vs this would be way more mass difference.
I modified the width of a trigger tech duty hammer to fit the slot in the bolt, which didn't take much doing.
Then I chopped it down some to match the existing trigger arc height to punch the back of the firing pin.
However, the trigger tech hammer doesn't allow for enough recess in the trigger group as the bolt rides back on recoil.
The Trigger tech is a no-go without them doing a significant revision to their design.
Then I chopped it down some to match the existing trigger arc height to punch the back of the firing pin.
However, the trigger tech hammer doesn't allow for enough recess in the trigger group as the bolt rides back on recoil.
The Trigger tech is a no-go without them doing a significant revision to their design.
Interesting. The B+T rifles suffer from a similar issue, where no aftermarket Triggers aside from Elftman will work for the same reason - their Hammers bind against the underside of the Bolt Carrier due to a lack of sufficient recess into the Trigger Group when the bolt moves rearward under recoil.
I will take a look at the Elftman frrom my APC 308 and report back.
No joy with the Elftman Match Trigger out of my APC 308. The Hammer is narrow enough to fit in the Firing Pin recess, however the striking face of the Hammer still binds against the bottom of the R9's Bolt during rearwards travel. As stated by Beltfed, the Elftman is also a no go without a redesign of the R9 bolt.
Unless SAI undertakes a considerable redesign, R9 owners are going to be limited to playing with different Hammer and Trigger Springs to try and lighten the 8lb(+) Trigger Pull.
Unless SAI undertakes a considerable redesign, R9 owners are going to be limited to playing with different Hammer and Trigger Springs to try and lighten the 8lb(+) Trigger Pull.
There are two listed on GP for $2800
Now THAT is a whole new level of attempted gouging! A mere 60% mark-up on a readily available item....There are two listed on GP for $2800
- Location
- Alberta, North America
I called - its Pre-order
