View Full Version : Alamo City Bolt and Striker

01-29-2007, 04:32 PM
Ok, so here are some photos of my newly arrived in the mail, Alamo City Bolt for the MR2 and the Striker Bolt for the MR2.

My thoughts on the products after visual inspection/comparison with the stock pieces:

Alamo City Bolt- First off, nice smooth cut of the bolt, no jagged edges or imperfections visible on the bolt itself. I purchsed red, for no real reason other than I just hate white bolts. I opted for the 3-orings, even though I use a force fed hopper currently, I figured it couldn't hurt have the extra oring as an option if I ever decide to try out a newer hopper like the fasta that isn't quite a force fed and may have issues with blow back from the bolt up the feedneck. So I will more than likely remove the third o-ring to save on wear and tear on my detents. Overall length of the bolt isn't exactly the same, it's almost an 1/8 of an inch shorter than the stock bolt. However I don't think it will be an issue since the length of the cocking pin to the front tip is the same, so it's only shorter on the back end. Also the ID(inner diameter) of the alamo bolt is smaller 3/8" to be exact compared to the 7/16" ID of the stock bolt. What effect this will have I'm not sure yet, but Burnouli's principle tells me the air flow will speedup and therefore will have a small drop in pressure. Probbaly not enough to really make a difference, might even be an improvement. also there are two(2) indentations for ball detents? Does the MR3 have 2 detents? Anyway, this bolt is advertised for the MR2/MR3 so I am assuming that's why it has grooves on both the left and right side of the bolt for detent travel. it's not an ACS bolt, but 'm almost interested in seeing the diffference and wonder if it will have any effect on chopping or if it even will stop the chopping epidemic. At this point I'm just too stubborn to give up on this marker. This bolt rang in at the price of $18.95 USD and I think it will do just fine and personally didn't feel it was a too expensive.

Next, the Alamo City Striker bolt- Now this one I am truly impressed with. I believe their website boasts something like 40 grams weight for this striker and if that is true, the stock striker must be close to 80grams because you can definately feel the difference in weight, so that tells me it's a substantial difference. If someone can verify the stock striker weight, you'd have a better idea of the loss of mass and reduction of recoil(better accuracy) you will achieve with this striker. It's made of hardened steel just like the stock striker except it it appears to be about 40% delron and the rest of the steel isn't as thick as the stock striker. I was originally going to try and lighten my striker by drilling, etc but hardened steel is no joke, so don't even waste your time attempting it. The valve pin is also longer than stock and Alamo advertises it as such as well, what this will do is allow the valve to stay open longer and may require some velocity adjustments and maybe even a stiffer spring for the striker to stay below 280fps. This striker cost a bit more than the bolt $29.95 USD but I think it will help reduce the recoil and kick from the marker and therefore think it will make a great upgrade to the marker.

Now I just need to debur my inner bolt chamber so I do not ruin my new bolt before updating with the results of the upgrade.

Any thoughts?

01-29-2007, 05:13 PM
nice job!
after you use the stuff, maybe a little more comparison, put it into the review section!

Hope this helps your gun!

darth massacre
01-29-2007, 08:30 PM
I really hope these new parts seal the deal for you. I dunno if you're still having major issues but if your MR2 still doesn't function as advertised then I really don't have much to say except toss it and get something else to shoot with.

01-30-2007, 03:26 PM
Hmm my bolt didn,t come with a pin and my striker doens,T fit : /

01-30-2007, 03:42 PM
Hmm my bolt didn,t come with a pin and my striker doens,T fit : /

Did you get a MR1 bolt? They don't have a pin.

01-30-2007, 05:45 PM
Ya prolly but the striker still doens,T fit it's too tight

01-31-2007, 02:03 AM
Glasher, if your striker is too tight, maybe the delron jacket swelled? Try some 400 grit sand paper and lightly sand the entire area evenly on the striker. Otherwise just send it back.

I didn't have any problems installing my alamo striker and it fit perfectly in my marker.

02-01-2007, 05:17 AM
Mine gets in the hole but it's very tight and offer some resistance when it enters and when I tried shooting with it to stoped recocking

02-03-2007, 03:40 PM
Ok, so more info on the striker, thought I would start there before adding the new bolt.

So i'm not as impressed as I first was with the product.

FIRST= The striker does fit into the hole, but like the post above this one, it's OD is a little bigger than the stock striker. In comparison to how the stock striker freely moves about into the chamber, the alamo city striker needs some sanding to achieve the same freedom of movement.

SECOND= After doing some light sanding, you can really see the imperfections in the milling as valleys and dips in the milling of the delron jacket becomes visible. I don't have any specialty measuring tools to verify if the thickness(OD) is consistent along the entire jacket of the striker. But from the look of the dips and valleys I would say it is not milled perfectly.

THIRD= The crevice for the spring is much shallower than the stock striker, this means with the alamo striker, you will have more striker spring tension as the same length of spring now has less room to work with. You can start to see the importance of this if you have ever done any spring mods and understand the difficulty to get things aligned and the marker to work correctly.

Fourth= The striker pin is longer on the alamo striker, which is going to open the valve for a longer time period than the stock striker, this how they claim it achieves a 25fps boost over the stock bolt. Now why you would care about a 25bps boost is beyond on me. This marker is already able to achieve over 300fps stock and I don't even know a field that will let you play over 280fps. Only advantage to this is if you were maybe using an apex and needed more air to achieve the same fps after the ball hits the ramp. I can't verify that though, I'm merely speculating.

FIFTH= the bottom groove that catches the sear has a much smaller surface area and the delron jacket encroaches into the area and might be a cause of my initial testing problems. (keep reading)

SIXTH= Installing the alamo striker after some extensive sanding with 320 grit sand paper to get a smoother slide in the chamber(after doing initial testing with zero modification to the striker) I reinstalled the stock spring and the stock bolt. Aired up cocked and fire...BBBRRRPT. The damn thing won't recock itself. Ok, so the striker isn't going back far enough to resettle back onto the sear. Shorten the spring? Well let's not trash the stock spring and break out the 32 degrees 9 piece spring kit. Try every spring and then start cutting the springs, no change whatsoever, the marker still won't re-cock. Well let's verify and reinstall all the stock parts(striker) and spring...ok back to normal again the marker is working as it should. So something definately up with the alamo striker/spring setup.

I've tried everything except change the valve spring, that's my next move once I get more air since now I am out.

Any ideas? I've searched the threads and no real info on what anyone has done to their striker's , etc.

Hob Hayward
02-03-2007, 05:16 PM
Well, first off, the point of an FPS increase that they claim is so then when you do an LP mod, you have a higher valve dwell which is necessary to get the velocities your normally get. Also a longer dwell should allow for easier recocking.

320 grit sandpaper is REALLY rough when it comes to these sorts of things, I would say use nothing less than 600 when polishing. ( I personally use 600 to start, and finish with 1500 grit. I'd say you most likely did more harm than good by "polishing" with that grit, especially ion delrin.

Also, you don't necessarily want as much fredom as the stock had, with less freedom, you'll have slower cycles perhaps, but you'll have a better seal (helps in recocking).

What I'd do is contact them and tell them about the failed recocking and see if it they had a few bad ones or something and they'll replace it.

02-03-2007, 07:11 PM
wow i had the same problem w/ mine. i just put it in the shop. Like ya said, no recock.

02-05-2007, 08:03 PM
I abandoned the striker it wouldn't fit and re-cock however, I've tried it on my g/f Pilo and it fited and worked pretty well.

As for the bolt is it normal that the o-tings seems to be a little bit under the surface ?

02-05-2007, 09:36 PM

The O-rings are some newer type called the quadra ring. They are new to me, I'm not sure if they are any better than a standard o-ring but yeah, my impression is the same in that they seam to be lower than the normal typical O-ring.

02-06-2007, 09:35 AM
I got the same set up a new bolt and striker. It helps save on gas b/c you now have to use a softer main spring than the stock. Changing the two items for me corrected my chopping and recocking problems. When I fire with balls in it functions fine, but dry firing it acts like its out of gas. I have not understood why it does this but I can now fire in any mode and that is what I wanted.

02-14-2007, 03:08 PM
So is it really worth buying? Im considering very soon on getting one.(like in 2hrs)

02-14-2007, 09:25 PM
The bolt definately is an improvement over the stock bolt in my opinion. The orings surrounding the blow through hole to the bolt helps with the blowback issues. However you lose the ACS option you have with the stock bolt. Personally I don't care for the ACS. That and I think many peoples issues with their markers have to do with the acs bolt and blow-back/by and the poor milling issues inside the bolt chamber that causes friction and scrapes the hell out of your stock acs bolt.

02-14-2007, 09:51 PM
hey viper....im guessing u have an upgraded bolt did that work or what? also did u have a lot of chopping issues with ur acs bolt before changing it?

02-15-2007, 05:30 AM
thanks viper, now i just need to get my dad to use his card but i still have to pay him for it..

03-14-2007, 05:23 AM
th the acs bolt and blow-back/by and the poor milling issues inside the bolt chamber that causes friction and scrapes the hell out of your stock acs bolt.

hi sorry for bringin' this back but this topic has the most information on the acp bolt/striker....

how do i avoid the bolt from being 'scraped'? i dont want the same thing to happen to my new bolt if i get it that has the same scrapes on my original...

BTW i suggest this be stickied...


03-14-2007, 06:34 AM
This is doing the same thing to me with my new bolt. I can see scratch on it ...

03-17-2007, 04:17 PM
anyone have an answer to mine and aliens prob?

03-17-2007, 05:56 PM
Hey, sorry for the late reply. The scraping on the bolt is caused by the bolt itself. The cocking pin that protrudes from bolt at the top that is used to recock the marker has a flat base that just protrudes up high enough above the delrin of the acs bolt and strikes the metal groove it slides in and smacks into the front of that groove inside your marker. This repetitive action everytime your marker fires causes the softer aluminum alloy metal of the receiver to deform from the hardened steel of the pin striking it. This causes two lil bumps to appear inside your bolt chamber and can be seen when you remove the stock, bolt and barrel and look down the chamber into the light. You will also notice the two grooves worn into your acs bolt caused by these "bumps".

I had to take a very fine file and slowly and carefully remove those bumps. That's the first part. Once that is done you will want to install the new Alamo bolt. If you stick the stock acs bolt back in and use it that way, the bumps will reappear over time as the original bolt is the source of this to begin with.

The good news is that the alamo bolt doesn't have this same clearance issue with the top cocking pin which is actually recessed at it's base into the delrin bolt.

Taking a closer look at the stock acs bolt, it does look like you may be able to slide the topcocking pin down a hair or two by loosening the allen screw that holds it in place. Just keep in mind you will most likely strip out the head on it, kingman used a thread locker on it and it is really in there good.

As for the striker, I've put that on the back of my list for now...it's going to take some time to dial it in and I'm currently working on going with a lower pressure on my MR2 and once that's done, I'll be back at trying to get the alamo striker to work. It's OD is too large with the delrin jacket and is larger than the stock striker and is causing too much friction which may be a good reason why it won't recock. Despite what others may think, you do not want friction but at the oring only to make a good seal when it comes to the striker.

04-04-2007, 10:14 PM
Well my experience with the alamo city bolt with 2 orings was'nt a good one. They sent me the wrong bolt the first time, no biggey I ordered another one . So i got it a few days later and oiled it up and threw it in my gun all excited about getting rid of all the blowback. It was still blowing out my feed neck , some people say that it minimized the blowback in their guns, in my case it did not. was'nt too thrilled, the square type orings on mine do not seem to protrude far enough out to seal the bolt chamber, and obvioslly they don't. Maybe the older style orings worked better? Anyone else having this issue with their Alamo city bolts? think i might go snooping around for different orings for this bolt

04-05-2007, 06:02 AM
Hmmmm weird cuz it made my MR2 better the popcorn effect wasnK't their anymore

04-05-2007, 08:17 AM
Samething happened to me. I continued to get the popcorn effect. I took some electrical tape and cut thin strips. took out all the o-rings and placed a SINGLE layer around the bolt and reassembled the o-rings. No popcorn after that.

04-05-2007, 04:45 PM
Good Idea Ksee777 I Think I'll Try That Instead Of Looking For Thicker Orings. Thanks.

Hob Hayward
04-05-2007, 05:55 PM
Also, I;d suggest using either grease or oil on the o-rings so they slide better, and seal better.

04-06-2007, 08:32 AM
don't wrap too much tape or it'll make your gun fart.