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MDT ACC Chassis
- Thread starter Saf3sh00t3r
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@MDT_OFFICIAL I think you may be missing an opportunity here. I think there is a large...and growing population of Big Magnum shooters with a short length of pull. I've heard people say they are compensating for something but I didn't get the jest of what they were talking about 
In reality...I'm a short guy...but monkey arms for my size. I run about a 14" LOP for a guy 5'6". I know at least 5+ people that run LOP's in the 12 to 12.5" range. When I let them shoot my rifle...they simply can't get comfortable behind it with their little T-Rex arms.
In reality...I'm a short guy...but monkey arms for my size. I run about a 14" LOP for a guy 5'6". I know at least 5+ people that run LOP's in the 12 to 12.5" range. When I let them shoot my rifle...they simply can't get comfortable behind it with their little T-Rex arms.
Shit, I’m your average 5-11 trex. And would love to be able to get up closer to my rifle.@MDT_OFFICIAL I think you may be missing an opportunity here. I think there is a large...and growing population of Big Magnum shooters with a short length of pull. I've heard people say they are compensating for something but I didn't get the jest of what they were talking about
In reality...I'm a short guy...but monkey arms for my size. I run about a 14" LOP for a guy 5'6". I know at least 5+ people that run LOP's in the 12 to 12.5" range. When I let them shoot my rifle...they simply can't get comfortable behind it with their little T-Rex arms.
Been thinking of adding a sling to my MDT ACC, but am new to these new fangled mlok quick detach things.
Rifle weighs in at 16.4lbs.
Should I be concerned or take any precautions with adding a standard magpul metal QD mlok adapter to one of the forward slots?
Rifle weighs in at 16.4lbs.
Should I be concerned or take any precautions with adding a standard magpul metal QD mlok adapter to one of the forward slots?
You’ll break well before the QD fitting, socket, or mlok bolt does.
Edit: assuming you avoid chinesium.
Thank you.
Both sling and mount are magpul branded items sourced through Brownells. They could be made in Fliplongdoo or the nation of Pineland, I figured they would be worth the extra couple bucks.
Currently MDT doesn't offer the ACC chassis in left hand for a tikka if the ever do I'll be getting rid of my MPA
I recently purchased the acc chassis and it’s by far more comfortable than my factory sendero stock with a kydex cheek piece. I was somewhat skeptical of a chassis but the overall design and setup is great.
@MDT_OFFICIAL @MDT_Josh
Today I was throwing some Krylon on the old MDT ACC Chassis to make it blend a little better into the weeds. For some reason I could not take my eyes off the bright red TriggerTech Diamond that was showing through when the bolt handle was lifted....so I take a rifle that was shooting great....and take the chassis off the barreled action and sponge paint the side of the trigger housing that was showing through. I also took this time to install a Hoptic quiver. Afterwards I installed the chassis just like your YouTube video and fired a 3 shot group to see where I need to rezero. It was already shooting 1/2" high due to zeroing at 28F the other week and today was 65F and seems that is the distance it will rise using Retumbo. Here is the results after taking the chassis off and reinstalling:
I was going to go for a 5 shot group but I chickened out...heh
My question to you is....is this your normal non shifting POI when re-installing a MDT Chassis...or is it due to my new paint job? Because I may have Uglified it....but she's beautiful to me:
Today I was throwing some Krylon on the old MDT ACC Chassis to make it blend a little better into the weeds. For some reason I could not take my eyes off the bright red TriggerTech Diamond that was showing through when the bolt handle was lifted....so I take a rifle that was shooting great....and take the chassis off the barreled action and sponge paint the side of the trigger housing that was showing through. I also took this time to install a Hoptic quiver. Afterwards I installed the chassis just like your YouTube video and fired a 3 shot group to see where I need to rezero. It was already shooting 1/2" high due to zeroing at 28F the other week and today was 65F and seems that is the distance it will rise using Retumbo. Here is the results after taking the chassis off and reinstalling:
I was going to go for a 5 shot group but I chickened out...heh
My question to you is....is this your normal non shifting POI when re-installing a MDT Chassis...or is it due to my new paint job? Because I may have Uglified it....but she's beautiful to me:
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@MDT_OFFICIAL I run NRL22 and PRS RimFire, and sporting a 18" barrel for ease of barricades/balance on rimfire. The ACC fore-end is too long but I absolutely love the chassis.
I'm considering having my smith lop off 2" from the fore-end and machine/round it off to work correctly. Do you have any concerns? I know I'll void warranty, etc... but I rather be happy running a tuned rifle that meets my needs. And any tips to the machinist to make sure I don't totally fubar my chassis will be nice too
I'm considering having my smith lop off 2" from the fore-end and machine/round it off to work correctly. Do you have any concerns? I know I'll void warranty, etc... but I rather be happy running a tuned rifle that meets my needs. And any tips to the machinist to make sure I don't totally fubar my chassis will be nice too
Or...he just likes to shoot
But if it's a 6mm Creed....with a Bartlein barrel...put in a MDT ACC...it is going to shoot sub half MOA.... what trigger you putting in it? TriggerTech Diamond set to <1lb I hope.
Chances are that the added paint changed your POI just slightly or it may have been torqued down to slightly different values? Either way, the v-block is machined to repeatedly hold your barreled action, meaning that if you were to re-zero and retry the test, you'd probably be a lot closer to zero without changing anything
Josh
@MDT_OFFICIAL I run NRL22 and PRS RimFire, and sporting a 18" barrel for ease of barricades/balance on rimfire. The ACC fore-end is too long but I absolutely love the chassis.
I'm considering having my smith lop off 2" from the fore-end and machine/round it off to work correctly. Do you have any concerns? I know I'll void warranty, etc... but I rather be happy running a tuned rifle that meets my needs. And any tips to the machinist to make sure I don't totally fubar my chassis will be nice too
There are no concerns doing this and one of our supported shooters, Adam in FL just did this to his own ACC
If you do it, be sure to re-drill and countersink the 4 screw holes that hold on the forend end-cap! Also, be sure to post pictures when you're done Josh
Or...he just likes to shoot
Trigger tech special. Saved a little money since I have to have a 2 pound or greater pull for the comps that I do. Less than a pound ain't going to change my shooting. I like more of the run and gun so less than a pound can be scary when your winded. It should have some good data on it before this year's Fort Meade which has been moved to peacemaker.
There are no concerns doing this and one of our supported shooters, Adam in FL just did this to his own ACC
Josh
Will do! I'm planning on getting another build/chassis in R700 in the future - either a V22 or Deuce (April). It'd be nice if you guys have that as an option
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There are no plans at this time. However, make sure to leave us a request!
MDT Chassis Systems, Magazines & Accessories for Bolt Action Rifles
Replace your factory rifle stock with an MDT Chassis System. Increase accuracy and performance, while also improving the look and feel of the rifle.
mdttac.com
@MDT_OFFICIAL
When did the shorter LOP start shipping? What's the current shortest LOP?
Also, can you run the MPA grip or an Ergo 0*
When did the shorter LOP start shipping? What's the current shortest LOP?
Also, can you run the MPA grip or an Ergo 0*
There is no exact date on when the shorter LOP's started shipping as it was a rolling change across all the inlets, with some moving higher volumes than others. The current, shortest LOP is 13-3/8" for the R700 SA RH inlet, but that will also vary slightly inlet to inlet and trigger to trigger.
Yes, the MPA grip and the Ergo 0deg both are adapted to the AR-15 grip interface, meaning that they will bolt right on our chassis without issue.
Josh
Iv thought about doing that , that's the only way to get a left hand tikka in ACC cause their not gonna offer them
MDT ACC Mag issues on Tikka.
I'm running a Tikka T3X 6mm CM. I shot a PRS match today, never had this issue before, but something would randomly happen to the mag position, not allowing to bolt to go forward. So I would have to drop it and reinsert it. Using a KRG mag with no binder..I just switched my action so only have maybe 20 rounds through it prior it this.. Any Mag recommendations? I would image the MDT ones are pretty solid?
I'm running a Tikka T3X 6mm CM. I shot a PRS match today, never had this issue before, but something would randomly happen to the mag position, not allowing to bolt to go forward. So I would have to drop it and reinsert it. Using a KRG mag with no binder..I just switched my action so only have maybe 20 rounds through it prior it this.. Any Mag recommendations? I would image the MDT ones are pretty solid?
There is a chance that the tip of the rounds were catching underneath the feed ramp of the Tikka if you are using handloads that are approaching 2.950"+. It is unlikely, but for very long rounds, that is a possibility.
Another option would be that the magazine was being pushed upwards whilst you were cycling the bolt (from a bad or prop) which was causing the tips of the feedlips to come up and block the bolt? That shouldn't happen on the Tikka due to the way that the magazine well is placed relative to the action, but again, there is a slight possibility.
What I would recommend is that you disassemble your magazine so that you just have the empty body, insert it into your chassis with the action in it, then flip the whole thing over and see if the inside face of the magazine will clear the bottom of the feed ramp. If it doesn't, then you may have to notch part of the feed ramp out for longer rounds.
We have this pretty well explained on the website:
Let me know if this helps
Josh
Thanks for the response Josh.There is a chance that the tip of the rounds were catching underneath the feed ramp of the Tikka if you are using handloads that are approaching 2.950"+. It is unlikely, but for very long rounds, that is a possibility.
Another option would be that the magazine was being pushed upwards whilst you were cycling the bolt (from a bad or prop) which was causing the tips of the feedlips to come up and block the bolt? That shouldn't happen on the Tikka due to the way that the magazine well is placed relative to the action, but again, there is a slight possibility.
What I would recommend is that you disassemble your magazine so that you just have the empty body, insert it into your chassis with the action in it, then flip the whole thing over and see if the inside face of the magazine will clear the bottom of the feed ramp. If it doesn't, then you may have to notch part of the feed ramp out for longer rounds.
We have this pretty well explained on the website:
View attachment 7257509
Let me know if this helps
Josh
Never had this happen while just out tuning the rifle, but I never put more than 5 rounds in the Mag.
I'm using factory prime ammo 107 . It happened I think on about every stage.. couple or more rounds into the mag. So are you saying I should be using one with a binder plate to prevent that if using factory ammo?
I didn't have time to look into the chamber to see what was happening when it happened. But if I released the Mag about an inch, and reseated it, it would chamber fine. So that leads me to think the mag isn't seating correctly for some reason. Could be a combination of both.
I'm going to try a MDT mag and see how that works.
I will try what you suggested and maybe posts some pic
It’s not got to do with the ammo, it has to do with whether or not your action allows be clear all the way or if it overlaps a bit at the end of the magazine. If it overlaps the binder plate helps fill up that that space under the action lip so that the bullet, any bullet, will not snag under the overhanging lip on its way up into the action.
Makes sense. It stated on the KRG site that tikkas dont need the binder so that's what I went with. I ran around 5 10 round mags through it last night to see if it would happen and it didn't. (not shooting) like you where saying, my bag my have been pushing the mag back. There is some play on the rear side of the mag but not the front.
Okay, so your ammo should be loaded at around 2.810" (if I remember correctly) meaning that there should be tons of room for the tip to clear the underside of the feed ramp. Magazine tilt shouldn't cause a round to jam forward, but the rounds shifting under recoil could cause them to slide forward and jam under the feed ramp, if indeed that is the issue. You also wouldn't really see that issue with only 5 rounds in the magazine but with a full mag, it could become apparent.
If you could take a picture of the underside of your setup looking into the magazine well through the mag, then we'd be able to tell pretty quickly
I'll see if I can get you some pictures to show what I mean.Josh
That's perfect! As you can see in the below photo with the circle, there is a little tiny bit of material that is over hanging the font of the magazine:
That would be just enough for the tip of the round to get stuck under if that is what is happening. I am slightly doubtful that is what's happening though as I also have my Tikka in an ACC and have run a lot of rounds through binder and non-binder plate magazines without any issue! Here are the same pictures from my gun:
What I would suggest is that next time you go to the range, load the magazine up to 10 rounds and run some drills or shoot normally. When you get a stoppage, don't try to clear it or drop your mag, but rather look in the ejection port and see if the tip of the round has cleared the feed ramp. If it has, then there is something else going on, if it hasn't then you;re going to need non-binder plate magazines.
Josh
You want the action to be slid all the way back in the stock so that the recoil lug is pressed against the chassis recoil lug pocket.
If there is space between the recoil lug and the stocks recoil lug pocket then there is space for the action to move around in and thats no bueno. You want it to be a solid connection.
Ya. I'm tracking that, I'm just wondering if I'm putting to much, which probably isn't possible I would think with the lug in place
I guarantee that the amount of force you’re pulling with is negligible next to that from a gunshot.
What weight are you guys running at for PRS?. I'm at 20lbs with all 5 internal weights and a PR carbon fiber barrel. I Don't like that much weight in the rear so I left it empty so far.
I have a few ACC's set up for NRL/PRS, NRL22/rimfire matches and some field matches. For the centrefire guns, I like to keep them at 22-24 lbs and the rimfire in the 15-18 lb range. That seems to be the "standard" now as people are shifting to heavier guns, but the weight is modular and adjustable to suit your needs.
Josh
I've got my ACC with 300PRC down to a slim trim 21lbs now....going to add maybe 1.5lbs soon with the difference in scope and mount. Going with the 5-27 ZCO MPCT3 with a Spuhr mount. That weight is with the Atlas Bipod, Hoptic quiver, and an empty MDT CIP mag. Add 5 rounds to the mag and 2 in the quiver and it pushes the weight up. Feels like a pig...kicks like a kitty.
@MDT_OFFICIAL I think you may be missing an opportunity here. I think there is a large...and growing population of Big Magnum shooters with a short length of pull. I've heard people say they are compensating for something but I didn't get the jest of what they were talking about
In reality...I'm a short guy...but monkey arms for my size. I run about a 14" LOP for a guy 5'6". I know at least 5+ people that run LOP's in the 12 to 12.5" range. When I let them shoot my rifle...they simply can't get comfortable behind it with their little T-Rex arms.
I just ordered a McMillan stock with a 12.5" LOP. I'm not a big guy, I don't have long arms. I was fortunate to have a couple old WW2 rifles around with a short LOP - they were informative and made the point, pretty clearly, that the industry standard 13.5-13.75 LOP is waaaaaaay too long for me.
There are a lot of good options out there, but if they cannot accommodate a <13" LOP, they're not even on the table for me. That can be doubly true if I try to get all fancy and modern straight behind the rifle versus bladed depending on the eye relief and mounting options of the scope.
I'm a short guy... 5'6"....but have long munkie arms I guess for my size. A 13.5" LOP seems fine to me. Checked it with the bent arm technique....fine...but simply sitting behind the rifle...I could probably go a little longer and still be more than comfortable. I think the adjustable grip distance for the ACC does more for me and my comfort than the LOP.
Yeah, I'm a weirdo that shoots "normally" w/o a bipod or unsupported. Stock fit is a fairly big deal for me when the rifle isn't sitting on top of something. That said, my shotgun has a full length stock on it - probably because I learned on guns that were too big for me and that just feels normal.
Listening to the podcast from Regina and Frank, you're also missing out on the whole competitive women market where anyone < 5'8 really shouldn't be running a LOP at 13.5". Regina mentioned for her size, she runs the McMillan A10 and is working with companies to provide chassis/stocks with shorter LOP. I think she runs like a 11.5-12"
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Thank you for the feedback; we are working on a solution at this time. Stay tuned!
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