Accuracy International AT-XC
- Thread starter R.Walters
- Start date
@diggler1833 yes my atx is gen1, folder, long bridge, high rail, gcp shoe.
Black Canyon Customs
Manzella Precision
Black Canyon Customs
I’m starting to think that AI bolt lift effort might be an individual gun variation thing. I guess I’ve noticed the same thing on R700 actions, but not Tikkas. I’m not sure how much of round-count plays into this.
I say this because I’ve read of fairly wide discrepancies in bolt lift effort between AI’s, and I’m not counting the new AT-XC action.
My new 2023 AT had a heavier lift than my bought-new 2021 AX, but not by too much. The AX had sub-1000 rounds through it. Sold the AX so I can’t compare it now that I have ~550 rds on the AT.
It’s probably all in my head lol
TL;DR
Don’t buy an AI if bolt lift effort is important.
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Checkmate lol damn you!
But I appreciate the correction.
The fuck I know man. Maybe it’s the 2003 bolt lugs causing near-immeasurable friction on an AI?
I wish I was an engineer.I totally forgot the TRG was 60°. Huh. It’s a lot lighter lift, I take it? How’s it compare to a Zeus?
I played with a used TRG-22 about 5-7 yrs ago at, of all places, Cabelas. That was before I got an AI and I don’t remember the bolt lift.
All I know is going by the two samples I have owned plus reader reports is AI = heavy bolt lift.
Lighter, smoother.
Going by the 4 AI’s I’ve owned (2-AT, ATX and AXMC) the ATX was noticeably worse. That was the only one with a comp trigger so maybe that had something to do with it. Maybe they had to make a few things stiffer to make the comp trigger safe?? Where the XC action could be redesigned for the trigger vs the other way aroundCheckmate lol damn you!
But I appreciate the correction.
The fuck I know man. Maybe it’s the 2003 bolt lugs causing near-immeasurable friction on an AI?
I totally forgot the TRG was 60°. Huh. It’s a lot lighter lift, I take it? How’s it compare to a Zeus?
I played with a used TRG-22 about 5-7 yrs ago at, of all places, Cabelas. That was before I got an AI and I don’t remember the bolt lift.
All I know is going by the two samples I have owned plus reader reports is AI = heavy bolt lift.
The AXSR has a decent trigger but I believe it’s its own design.
I never dug into why it was so much different although it’s the same action in previous AT and AX models
In general AI are heavier. More than my tikka ctr. But less than my wife’s savage.
But there’s AI heavy then there’s heavy for an AI heavy
For fun, I just measured my AX and my AX50 with a digital trigger pull gauge (measured from right in front of the ball, so subtract a pound or two for actual required required force): The AX measured a consistent 10lbs, and the AX50 came in at a consistent 12.1lbs. I have no problems whatsoever operating the AX, but recall the TRG(42) being a little more fiddly (probably because the rear of that rifle was way, way lighter than the AIs). The AX50 requires noticeable effort, and I wouldn't have it any other way.
Sounds about right. I taped a paracord to the bolt knob. My AT’s are 8-9lbs and my ATX topped out a 12lbs trigger scale and still didn’t budge. I say it’s around 12 lbs but I’d estimate it was closer to probably 14lbs
With the AI being 60 degree bolt lift and if you want to maintain a normal amount of firing pin travel for a centerfire action, there's only so much you can do to lighten the bolt lift-- X distance of spring compression must be applied to a spring of Y spring rate over Z degrees of bolt rotation.
Surface finishes and lubrication can certainly help, along with cocking piece and cocking ramp geometry, as well as the bolt lug camming/ramp surfaces (since the AI has some cocking on close, smoother chamfers/radii on the bolt lugs would help smooth the bolt closing as it compresses the firing pin spring when closing the bolt) but there's only so much you can do trying to do the same amount of work when compressing the firing pin spring in 60 degrees of bolt rotation.
If the action stays 60 degrees and you wanted to lighten the bolt opening effort you could decrease the amount of cocking on open and increase the cocking on close which would make for a rougher and higher effort bolt closing, reduce the amount of degrees devoted to the extraction cam in order to spread out the cocking ramp over a few extra degrees of bolt opening rotation which means the bolt lift may be lighter but now you may have to give the bolt handle a firm upwards smack in the event of a stuck case since you'll now have less of an extraction cam and less primary extraction force, or reduce the firing pin travel or reduce the firing pin spring rate at the expense of less energy delivered to the firing pin and primer. You could also narrow the cocking piece so more of the bolt rotation could be used for a shallower cocking ramp, but now you're concentrating the spring pressure on a narrower contact patch on the cocking piece and cocking ramp and that same force concentrated on a smaller surface area may have more friction. You could try combinations of all of the above, and probably some other things I missed, trying to lighten and smooth the bolt lift and close.
And there's the easy way out-- leave things as they are and lengthen the bolt handle to provide additional leverage to reduce the "perceived" bolt lift effort.
I keep wondering how much you could reduce the firing pin spring rate on an AI before reliability is adversely affected... The AI firing pin spring is pretty hefty for maximum reliability, but I'm sure some people would be willing to risk it not always going bang when the action is filthy to have a lighter and smoother bolt lift in normal use. A few years ago I measured the firing pin spring on my AT and I think it was somewhere about 26# when compressed to the fully cocked position. I have a hunch you could probably drop it down to 18-20ish pounds and substantially lighten the bolt lift and still have it ignite primers reliably unless the action was really dirty.
Surface finishes and lubrication can certainly help, along with cocking piece and cocking ramp geometry, as well as the bolt lug camming/ramp surfaces (since the AI has some cocking on close, smoother chamfers/radii on the bolt lugs would help smooth the bolt closing as it compresses the firing pin spring when closing the bolt) but there's only so much you can do trying to do the same amount of work when compressing the firing pin spring in 60 degrees of bolt rotation.
If the action stays 60 degrees and you wanted to lighten the bolt opening effort you could decrease the amount of cocking on open and increase the cocking on close which would make for a rougher and higher effort bolt closing, reduce the amount of degrees devoted to the extraction cam in order to spread out the cocking ramp over a few extra degrees of bolt opening rotation which means the bolt lift may be lighter but now you may have to give the bolt handle a firm upwards smack in the event of a stuck case since you'll now have less of an extraction cam and less primary extraction force, or reduce the firing pin travel or reduce the firing pin spring rate at the expense of less energy delivered to the firing pin and primer. You could also narrow the cocking piece so more of the bolt rotation could be used for a shallower cocking ramp, but now you're concentrating the spring pressure on a narrower contact patch on the cocking piece and cocking ramp and that same force concentrated on a smaller surface area may have more friction. You could try combinations of all of the above, and probably some other things I missed, trying to lighten and smooth the bolt lift and close.
And there's the easy way out-- leave things as they are and lengthen the bolt handle to provide additional leverage to reduce the "perceived" bolt lift effort.
I keep wondering how much you could reduce the firing pin spring rate on an AI before reliability is adversely affected... The AI firing pin spring is pretty hefty for maximum reliability, but I'm sure some people would be willing to risk it not always going bang when the action is filthy to have a lighter and smoother bolt lift in normal use. A few years ago I measured the firing pin spring on my AT and I think it was somewhere about 26# when compressed to the fully cocked position. I have a hunch you could probably drop it down to 18-20ish pounds and substantially lighten the bolt lift and still have it ignite primers reliably unless the action was really dirty.
I do not lol. I didn't fit the bill to get a department use gun so I made my own lmao. Chop chop ! Used Sig Dark Grey for my cerakote color. It's close enough for me.
I have an AI-AX that now sits in an AT-X chassis, an AT-X and have a bit of time behind an AT-XC. Out of the three my 2018 AX action is the best, then the AT-XC and lastly my 2022 AT-X. The AT-X and AX both have standard AI triggers, although I am confident when I say that does not effect bolt lift. Previous posts about a 60deg action having a heavier bolt lift vs a 90deg is a universal truth. My personal thought is AI improved the AT-XC by lightening the firing pin spring weight (they also redesigned the bolt in some capacity as they are not interchangeable but I do not know enough details to speak to that).
As far as addressing the bolt lift and especially the 'hitch' on close that I can not stand on new AI actions this can be fixed. Take fine (1200grit +) lapping compound on the bolt lugs as well as the cocking ramp and run the action a bunch. In the intermediate safety position with the firing pin removed from the equation there should be no hitch or weight felt and the action should glide in and out of battery. If this doesn't occur you need to remove material from somewhere, use prussian blue to see where there is incorrect metal on metal contact or high spots. The hitch can be caused by the action geometry itself as you go to close the bolt and can be fixed by removing material from where the bolt handle contacts the action (**this is something AI addressed with the AT-XC as the action doesn't have a sharp 90deg angle where the bolt handle cams downward**).
As others have previously stated, firing pin strength has a large impact on overall action feel and cocking weight. I have no idea what AI firing pin weight is - I do know some folks have messed with removing coils to lighten the cocking weight but that in turn can have an impact on reliability by causing light strikes.
Ultimately these guns will never feel like a TL3 or an Impact by design but my 18AX is pretty damn good and I wouldn't change a thing. That gun has also seen a fair amount of rounds and as these guns work in and the springs see use that helps more than anything and although the lapping compound can help accelerate wear there is no replacement for use and familiarity.
I found a quantifiable benefit to accuracy when I bonded both my AT-Xs. I think its bullshit AI stopped bonding these rifles and publishes that bonding is no longer needed, I can say in my case that simply is not true. Lastly, I can take some photos of areas where I have seen lapping compound be the most beneficial if there are any folks curious enough for this to be of value.
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The AT-XC is an improvement over the AT-X but not for the price difference and after lapping the action my AT-X is much smoother, just a tad heavier an an AT-XC and my 18AX. As far as bonding you can access the trigger, really service everything except the rollpin for the bolt stop.
I agree with this. It's not a worthy upgrade if you already have an AT-X, but if you are looking to pick up your first short action AI then I think the juice is worth the squeeze.
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Ordered an AT XC from Eurooptic yesterday and was pleasantly surprised with the price. I tried to find a used ATX that I wanted, but none of them moved the meter for me like the XC did. Hope to have it in hand this week.
Side note: does anyone's factory 6 creed barrel show a preference in factory ammo?
Side note: does anyone's factory 6 creed barrel show a preference in factory ammo?
They have a demo LH AXSR that has me thinking
Sheeityou will burn through it in 1000 rds
Prime 107s
Must have left some oil in chamber settled back down to its normal 3154 after a mag or 2
Manzella 28”.
Prime was the shit hot and accurate
Their 130-grain 6.5 Creedmoor was money. I still have a few thousand rounds, but use it sparingly.
Put 5 of 12 on a new 10"/1 MOA gong I hung at 1000 this morning with the factory 6.5 Creed barrel. I was shooting Hornady factory loaded 140 ELD-M.
OK, I like the AT-XC better than my Sako now, after 450 or so rounds and a lot of dry firing, the bolt is getting slick. The chassis is really well designed too
I am at roughly 500 rounds now and it's 20-30% better than when it was new. Very happy thus far.
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