New Rock Creek / Muller Works MI barrel install

[rkcal22]

I scored most of the targets in the match that John is talking about and would like to mention something . As shooters when we get a good score we "feel" good but yestertoday as a scorer I felt good when on one of Johns target his first row had 5 x's all lined up left to right. It is a beautiful sight to see all of those little holes punched out dead center. Good shooting . Richard

 

[crb]

Ray, Pete W has graciously offered to do just that for me as I don't have a bore scope or any idea of what to look for. I may know more Sunday. Its a great group of guys in this sport it seems as the guys I shoot with have been helpful & a lot of you here on the forum have been as well. Thanks guys!
Keith

Have Pete show you what a land is and what a groove is. The lands are the top of the rifling and the grooves are the bottom.

The leade is the first place to closely inspect. This is the area of the rifling that the reamer cuts to a shallow angle so that the bullet can be gently and progressively engraved by the rifling as the bullet starts down the bore. Most match chambers have the bullet pushed into the leade as the bolt is closed.

Look at one land a short distance in front of the leade. Now start slowly withdrawing the scope and observe the land as it transitions to the leade. What you want is for the leade to be the exact same width of the land. Often what you see is the leade is slightly wider than the land due to burrs that are a normal part of any reaming that is done on an interrupted surface. The interrupted surface here is the rifling's height up above the grooves.

Then look at the other lands. Make sure they appear 100% consistent with one another.

Every time the bullet enters a leade with these burrs there can be metal stripped off the bullet and the engraving of the bullet is now wider than the width of the rifling just beyond the leade resulting in a sloppy fit. Also any lead stripped off the bullet builds up shot after shot screwing up the engraving even more. Eventually this lead build up can be carried away by a bullet. Needless to say that bullet doesn't go anywhere near the poa.

Also the surface of the leade at each land may be rough. It will look like a fine toothed file with the teeth at right angles to the bore. You can imagine what this roughness will do to the bullet as it engages the rifling.

What you need the chamber to do is as gently as possible create a path for the bullet to enter the bore without being damaged or having metal stripped off. You need the bullet to be a perfect fit in the bore. I polish my chamber and leade with Flitz after using a split arbor and worn emery paper to smooth the leade and eliminate the burrs. There has to be a better way than the split arbor but I haven't come up with anything. Some use a "hob" but they are quite secretive about this.

WARNING. I am an idiot that has no clue what he is talking about. Use info at own risk.

 

[center22]

What you need the chamber to do is as gently as possible create a path for the bullet to enter the bore without being damaged or having metal stripped off. You need the bullet to be a perfect fit in the bore. I polish my chamber and leade with Flitz after using a split arbor and worn emery paper to smooth the leade and eliminate the burrs. There has to be a better way than the split arbor but I haven't come up with anything. Some use a "hob" but they are quite secretive about this.

WARNING. I am an idiot that has no clue what he is talking about. Use info at own risk.

Ray,
They sell Felt Polishing Burrs on Ebay and they are very inexpensive. The closest size is 1/4" inch (.250"), they work extremely well for polishing a rimfire chamber. They are hard felt and somewhat oversize, but they can be worked down easily too fit snugly into the chamber. I leave one permanently in a chambered cut off piece of barrel, to retain size and keep it free from picking up contaminants.
Chuck the Felt Polishing Burr up in the tail piece of a lathe or simply use it in a dremel tool, portable drill, etc. Only use very fine polishing compounds, as lapping compounds will increase the chamber dimensions to much. Same company has others sizes to 1/2" that work extremely well for other gunsmithing tasks and an assortment of excellent polishing compounds. Thanks for providing the tips on using a bore scope. John

http://www.ebay.com/itm/140926155209?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

 

[center22]

More on the XIII / RC/Muller barrels consistantcy

We hold three USBR BR matches per month at HRPC. Two are regular matches, one is a practice match and club records can not be set, or broken during a practice match. Saturday, July 27th was a regular club match and I went back to my XIII unlimited rifle, shooting from a Pappas rest.

My scores for the aggregate were: 244 8x / 249 8x / 244 6x = 737 22x for a 1st Place. 2nd Place a close 734 18x by Jerry G, and 3rd a 727 18X by Richard K. with 7 unlimited shooters. The 249 8x [shot in the rain] has been my highest scoring USBR yet, as I chase the elusive 250, which I'm told are quite rare in this discipline.

Today, I went to the range for a practice session, my lady friend refers to it as ... "getting my therapy". Decided to shoot some even more challenging targets ... the PSL! I fired the first PSL target using Eley Team 1012-04045 for a score of 1950 8x / 2nd PSL using Eley Match 1012-02335 for a score of 2125 8x / 3rd PSL using Eley Match 1012-06424 for a score of 2250 15x. I am pleased with the way the XIII/RCM has been shooting! John

I took some photos today of my equipment set up on our new one piece [poured into a custom made mold] concrete benches, which we now have twelve. They are excellent!

 

[crb]

There's no way a rifle is going to shoot competitively with the firing pin pounding the crap out of the edge of the rim like that...................................................................................... .................................



:thumbsup:

 

[Slick Willy]

Extruded Benches

I took some photos today of my equipment set up on our new one piece [poured into a custom made mold] concrete benches, which we now have twelve. They are excellent!

John, the benches look nice! Never seen any like them ,Does some one commercialy build them ? What would be the cost of one?

 

[center22]

Benches

John, the benches look nice! Never seen any like them ,Does some one commercialy build them ? What would be the cost of one?

Slick Willy,
One of our club members named Nikki P. pre-fabricated a mold made from sheet steel and wood. He assembled the mold with nuts, bolts and screws into a one piece unit for pouring. Then he pre-fabricated 3/8" rebar, that he tack welded together at his home. Then he placed the assembled re-bar unit into the mold. Each bench required around 12 1/2 - 80 lb bags of concrete, which were mixed in a small electric mixer, along with one member assisting as a laborer. The pour concrete sat in the mold for a minimum of two days before the mold was disassembled. If you take notice, the edges are even beveled. Nikki is one of those ex-military perfectionists. Many club members donated $200.00 per bench, to cover cost of materials ... labor was free. All toll, the benchrest project took the better part of four or five months. They are painted Hunter green. Nikki may have the mold for sale, as it is his design and belongs to him. John

 

[crb]

The benches look great but imo the bevels should be eliminated from the mold at least in the shooter cut-outs. That bevel keeps you from getting a rear bag as close to the edge as possible.

 

[center22]

The benches look great but imo the bevels should be eliminated from the mold at least in the shooter cut-outs. That bevel keeps you from getting a rear bag as close to the edge as possible.

Too late for us now, but I haven't heard a complaint either and we have our share of bag squeezers.

 

[rkcal22]

CRB That's a good point about the bevel but most of the shooters shoot "free style" and as of yet I haven't noticed that the bag was to far away . The bevel is minor in the angle and I think a bag can be put to the edge without taking anything way from support. I'll make a test this Friday . By the way John and most of the unlimited shooters use a 1 piece rest, not me . Richard

 

[Pete Wass]

I don't care fot this style bench

I prefer benches that are shaped more like "Home Plate". I like to get behind my rifles and not drape over them. I don't like benches that have a 90* angle that is going to stick into my fat belly . I also don't like benches that are over 42" long. I fully understand that I am an individual with personal likes and dislikes and don't mean to condemn these benches in any way.

 

[center22]

Frustrating Practice Session Yesterday!

Frustrating Practice Day using PSL targets...

For those who have been following this thread since I installed a new Rock Creek Muller MI barrel on my XIII action, know that I have been quite up-beat about the rifles accuracy. Well yesterday, things changed for the worst.

When I built the rifle, all the components were new, except for the Jewel BR trigger. which was removed from a 40X rifle I purchased used. In the mean time, I had bought a brand new Jewel BR trigger for a tentative build, that I am waiting for a new action. Recently, I had a couple accidental discharges when I closed the bolt handle forcefully, because the used Jewel trigger was set very light and shows some heavy wear points on the melonite finish. I'm certain, small adjustments with an Allen wrench would have solved the AD issues, but I said to myself "what the heck", just go ahead and install the brand new Jewel trigger, that's sitting idle on the work bench. I installed the new trigger with the factory settings, re-torqued the action screws to 35 inch pounds, then headed to the range for a practice session.

Eley Match ammo that shot very decent scores the week before from this same rifle, was now very erratic, like the rifle was completely out of tune! I shot three PSL targets with very low scores of 1450 5x, 1875 7x, 1700 9x. A week ago, the same rifle shot scores of 1950 8x, 2125 8x, 2250 15x. Can something a simple as replacing a factory Jewel trigger have this much of a drastic effect on overall accuracy? Now ... I must say the wind conditions yesterday were worst than the previous week, but nothing that should have caused that much disparity.

Last night, I checked the trigger pull on the new Jewel trigger with the factory settings and it was right around 6 ounces ... much more than I would have thought ... being they advertise right around 2 ounces. I made a few adjustments and now have the Jewel trigger set around 2.5 ounces. Will make time to re-test the rifle before our next club match on the 14th. I will take the old Jewel trigger with me, just case I want to re-install it! John

 

[crb]

A used Hall I bought had an issue with the striker following occasionally when closing the bolt. It wouldn't AD it would just not be cocked. Adding just a minute amount of additional sear engagement fixed it. Probably wasn't even an additional 1/8 of a turn on the screw.

When I get a rifle shooting good I don't like to mess with it, especially removing the action from the stock.

 

[linekin]

Temp or Humidity

John, you mentioned the wind may have been a factor. How about the temperature or humidity? I was having fits a while back when they both were up & condemned some ammo I previously thought was ok. Temps have settled back down & my gun likes the ammo again & is behaving. I'm its problem now.
Good luck! I'm sure you'll figure it out.
Keith

 

[center22]

Ray,
You are correct. A 1/8 turn counter clockwise on the sear engagement screw #1, plus a 1/8 turn clockwise on the trigger pull force screw #3, would have solved the problem with the AD's.

Keith,
You could be right about the heat and humidity affecting the ammo as it was stored in a non air conditioned environment. It is extremely hot and humid this time of year, here in south Florida. I know of at least one prone shooter at the club who brings his ammo to a match and all practice sessions in a small cooler. Thanks, John

 

[crb]

It would be interesting to put some of your ammo in a cooler and some at ambient and fire it on a hot day.

 

[center22]

It would be interesting to put some of your ammo in a cooler and some at ambient and fire it on a hot day.

I will perform some ammo testing as you suggest and let you know the results.

 

[crb]

Ray,
You are correct. A 1/8 turn counter clockwise on the sear engagement screw #1, plus a 1/8 turn clockwise on the trigger pull force screw #3, would have solved the problem with the AD's.

I keep a set of Jewel instructions in my toolbox that goes to the range.

 

[center22]

"Keeping Your Ammo Cool" testing

John, you mentioned the wind may have been a factor. How about the temperature or humidity? I was having fits a while back when they both were up & condemned some ammo I previously thought was ok. Temps have settled back down & my gun likes the ammo again & is behaving. I'm its problem now.
Good luck! I'm sure you'll figure it out.
Keith

Keith,

I was at Wally World a few days ago and purchased a small soft sided (six pack) cooler and a large Coleman Chiller (ice substitute).

Several days prior to a club match, I relocated the ammo that I was going to use to an air conditioned area of my house. The night before the match, I placed the Coleman Chiller in the freezer. The morning of the match I put the my match ammo in the cooler along with the Chiller (substitute ice) using the plastic compartment separator between the Chiller and the Eley Match ammo. About fifteen minute before each match target, I removed one box of ammo from the cooler and placed the bullets in my wood tray, to warm up some, before the relay began.

This test seemed to work out OK, as all three USBR targets had the same point value ... 246 8x / 246 7x / 246 8x ... very consistent. During extremely hot days, this procedure may help some shooters. John

 

[linekin]

I may have to try that John. I was having fits with my rifle in the heat in July. Temps are a little cooler here in ME lately & it seems to have settled down. Anyhow I'm glad things have settled down for you as well.
Keith