Author Topic: How to squeeze a little more accuracy out of a 1377+ (Read 2859 times))

jim p · « **on:** February 12, 2017, 12:05:20 AM »

I put a steel breech kit on the gun and a 14" crosman barrel and a stock and a 6x24x50mm scope. Sometimes I get to see the pellet hit the same hole and then I get to watch the pellet hit 3/4" from the hole.

What else can be done to get a little more accuracy. Oh I have tried different pellets. I am thinking about getting a 24" barrel and see how it does.

I have a custom 1300kt with the lothar barrel and it shoots pretty well so I am thinking about putting the better scope on it and seeing how well it will do.

BenjiHunter · « **Reply #1 on:** February 12, 2017, 12:12:53 AM »

If you can find an aluminum or brass barrel band, it will increase your accuracy.
http://www.canadashootingsupply.ca/brass-barrel-band-for-crosman-1377-1322.html

Gertrude · « **Reply #2 on:** February 12, 2017, 12:44:44 AM »

Crosman Pumper Mods 101-
A disco bolt probe (or a home made extended probe) will help in getting the skirt of the pellet past the transfer port.
A 18" barrel is about the max length that a pumper will benefit from.
A recrowning of the muzzle sometimes can help tighten the groups.
Polishing the contact points, and shimming of the trigger group can also help deliver a cleaner break.
Stiffening the piston and shimming the piston cup is a budget way to squeeze a little more performance... or going to a flat top piston and valve is even better.
Changing the transfer port seal to a piece of icemaker tubing has also had positive results for many of us.
Adding a 1399 shoulder stock will also help, if you are interested in it being a Carbine.

Hope this helps

jim p · « **Reply #3 on:** February 12, 2017, 04:23:21 PM »

There is one thing that bugs me. When I close the bolt on the pellet, it seems like a little click. I think that this click is caused by the pellet being forced into the rifling. I looked at the barrel before I installed it and I didn't see any burs.

Do you guys know what is causing this click when the pellet is chambered?

The crown on the barrel is a little strange. It looks like the crown was recessed into the barrel. I don't think that I can recrown the barrel without removing about 1/8" from the front of the barrel.

Have you seen any crowns made like this? Is this a good method of making a crown?

dv8eod · « **Reply #4 on:** February 12, 2017, 04:59:38 PM »

The click you feel may be the oring on the bolt seating into place so it can seal.

CraigH · « **Reply #5 on:** February 12, 2017, 05:10:36 PM »

Do you have a standard crosman front sight? If so you may be seeing the barrel down inside the front sight. If you pull of the sight you can examine the barrel crown.

jim p · « **Reply #6 on:** February 12, 2017, 06:17:45 PM »

The barrel does not have a front sight.

tennx · « **Reply #7 on:** February 12, 2017, 06:24:37 PM »

Quote from: jim p on February 12, 2017, 04:23:21 PM

There is one thing that bugs me. When I close the bolt on the pellet, it seems like a little click. I think that this click is caused by the pellet being forced into the rifling. I looked at the barrel before I installed it and I didn't see any burs.

Do you guys know what is causing this click when the pellet is chambered?

The crown on the barrel is a little strange. It looks like the crown was recessed into the barrel. I don't think that I can recrown the barrel without removing about 1/8" from the front of the barrel.

Have you seen any crowns made like this? Is this a good method of making a crown?

My 397 makes click when I chamber a pellet...I believe its the pellet hitting the transfer port.....good luck

BenjiHunter · « **Reply #8 on:** February 12, 2017, 08:22:31 PM »

Mine makes a click.

nervoustrigger · « **Reply #9 on:** February 13, 2017, 12:08:48 PM »

Jim, the crown on Crosman's barrels have a slight bevel. In other words, a slight conical recess. Is that what you are seeing?

The bevel should be uniform and absent of a burr. Uniformity you can check visually. To see if there is a burr, you can gently pull a cotton swab over it to see if it snags, although I prefer to push a couple of pellets through because in my experience it's more reliable at finding a slight burr.

Also, see here for info on another form of crown damage that some people have experienced with Crosman barrels.
http://www.gatewaytoairguns.org/GTA/index.php?topic=110179

jim p · « **Reply #10 on:** February 13, 2017, 09:50:19 PM »

I just did a good cleaning of the barrel and then I did a close visual inspection (cvi). The cvi revealed the small straight line down the barrel. Everything else looked great. The rifling was clean and not marred. There were no marks left from a crowning tool. The crown looks symmetrical although it looks like a double angle crown.

I took a pellet and used the bolt to push it into its starting position. I then removed the pellet by pushing it back into the breech. The head of the pellet had rifling marks and the skirt didn't have any rifling marks. I think the click that I have been feeling when pushing the bolt forward is the head of the pellet being forced into the rifling.

Should I try to increase the length of the probe so that the skirt of the pellet would have rifling marks? This would ensure that the pellet is past the transfer port.

kj · « **Reply #11 on:** February 13, 2017, 10:46:18 PM »

an extended probe is a good investment. getting the skirt past the transfer port is always good. a good trigger is always helpful in attaining good accuracy. replacing your trigger group with a p-rod trigger group will give you a much better 2 stage trigger.

peace
kj

jim p · « **Reply #12 on:** July 28, 2017, 07:15:15 AM »

I have just been living with a crappy shooting gun for the last few months. I also have a hatsan 95 vortex and a 1300kt in .22 cal. They are all shooting below my expectations.

I guess that I am just not an air gun shooter.

Maybe if I got some match grade pellets, then I could get better accuracy but that kind of defeats the purpose of having a gun that shoots inexpensive ammo.

maraudinglizard · « **Reply #13 on:** July 28, 2017, 07:36:46 AM »

The JSB pellets do well in the Crosman Custom guns, I use the RS diabolo .177 in my 1300kt LW barrel and 2400kt. H&N is another to look at as well. Good Luck.

Hoosier Daddy · « **Reply #14 on:** July 28, 2017, 07:45:16 AM »

Quote

I guess that I am just not an air gun shooter.

WHOA... Don't be so hard on yourself! Don't give up yet.
If I would have thought my 1377 out of the box, or the POS Hatsan 95 I got, was as good as it get's I might have felt the same.
I was buying cheap entry level guns when I got into airgunning. I was happy to hit a coffee can at 20 yards.

The biggest improvement to MY 13XX was smoothing the contact points of the trigger by following THIS VIDEO
The Hatsan 95 was returned because of it's issues.

In my experiance.... if you're buying "Big Box Store" pellets that don't say Crosman PREMIER... you are wasting your money.

Since then I have learned with the help of GTA you have to learn airguns are not Powder Burners and the HOLD is a lot of the game to accuracy. Especially with Springers, yes your Gas Piston Vortex is still a "Springer"
Then there is the simple fact you can't make a silk purse out of a sows ear... well sorta. You can do a lot to a 13XX to improve it.... But if you are looking for match grade accuracy you need to step up and get a "good" gun.

moorepower · « **Reply #15 on:** July 28, 2017, 01:07:08 PM »

Quote from: jim p on February 12, 2017, 04:23:21 PM

There is one thing that bugs me. When I close the bolt on the pellet, it seems like a little click. I think that this click is caused by the pellet being forced into the rifling. I looked at the barrel before I installed it and I didn't see any burs.

Do you guys know what is causing this click when the pellet is chambered?

The crown on the barrel is a little strange. It looks like the crown was recessed into the barrel. I don't think that I can recrown the barrel without removing about 1/8" from the front of the barrel.

Have you seen any crowns made like this? Is this a good method of making a crown?

I will bet it is like almost all of my Crosman barrels and was crowned with a piloted tool, and when they did it it wiped the rifling. I cut off about 1/4" and recrowned all mine and now "mostly" they shoot.

jim p · « **Reply #16 on:** July 29, 2017, 08:38:47 PM »

Thanks for the tips. I have checked the barrel for damage and it looks good. I am going to try some match grade pellets and if that does not work, then I will just shoot cans and forget it. At this time there is just not enough accuracy in the guns to keep me interested.

I have polished triggers and replace roll pins with solid pins.

It is pretty crazy to watch a pellet fly off target while looking through the scope and seeing the cross hairs stay on target. The pellet just moves away from the cross hairs and it may move up, down, left or right up to one mil dot away at 20 yards.

mentolio · « **Reply #17 on:** July 31, 2017, 08:43:10 AM »

Even the higher end pellets have the occasional "bad pellet." It may be worth your while (and I can't believe I'm saying this) to "sort" your pellets by size and weight (ugh!). It's a lot of work, but increasing you pellet to pellet consistency may really help to eliminate the fliers. I will not do this, and so just buy H&N Field Target Trophy pellets, and live with an occasional bad'un, which doesn't seem to be happening nearly as often for me as with other pellet manufacturers. Best of luck, hope you get things "sorted" (pun intended).

moorepower · « **Reply #18 on:** July 31, 2017, 11:18:47 AM »

It is possible that you might be better off with a 5.53-5.54 or 5.55 head H&N ftt. My PRod shoots the 5.54 ftt pellets much better than any other pellet I have tried. It shoots the JSB's like a shotgun.

Hoosier Daddy · « **Reply #19 on:** July 31, 2017, 12:42:07 PM »

Quote from: moorepower on July 31, 2017, 11:18:47 AM

It is possible that you might be better off with a 5.53-5.54 or 5.55 head H&N ftt.

Not likely... the 1377 is .177

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How to squeeze a little more accuracy out of a 1377+

Author Topic: How to squeeze a little more accuracy out of a 1377+ (Read 2859 times))