Do i need to scrag the main spring

[vbull]

Someone told me the other day that I need to scrag or set the new mainspring I just bought for my Webley Mark 3 before fitting it, is this true ? The only online reference I could find about this was on the Pyramid Air site.

[Rickenbacker]

Depends... Did you buy it from the 19th Century?

[Benelli B76]

I do not see the point of it. For instance I just repaired a rifle that had an old spring. The spring wire was 2.8 mm dia with 34 coils. 34 x 2.8 =95.2 mm total compressed length. The new spring I had to put in had 3.0 mm wire, 95.2 divided by 3.0 =31.73. I had to cut this spring down to 31 coils so that when it fully compressed it would still fit in the rifle and not block the sear engagement.If the spring slowly collapses in length over time it still is going to fill the same space when compressed. Of course you must also chrono after fitting as the new spring may take the power over 12ft lbs and need futher reduction.( Just seen my posts have reached 666, The Mark of The Beast, definitely not me.)

Baz

[vbull]

The spring I bought from Dave on here, a genuine old stock Webley one. I've renovated firearms of all descriptions over the years but never done a springer air rifle so I'm a bit unsure on some things which is why I'm asking about this. The guy on the Pyramid Air vid says it should be done in all cases, as did the bloke I was talking to the other day, and they are talking about modern stuff as well as old, personally I can't see the point except it will make the new spring easier to fit so I don't have a clue what they are on about. Is this something that was done mainly in the old days with inferior steel springs, and what are the advantages of setting a spring nowadays, if any at all ?

[MattyBoy]

Putting the spring in the gun and cocking it pretty much acheives the same effect IMO - maybe not to the coil-bound "solid" state that scragging entails but pretty close to that in a lot of guns.

I am not sure why one would go to the trouble of scragging outside the gun first...

Matty

[Garvin]

Someone told me the other day that I need to scrag or set the new mainspring I just bought for my Webley Mark 3 before fitting it, is this true ? The only online reference I could find about this was on the Pyramid Air site.

US tuner Charlie Da Tuna says:

Setting springs
By CharlieDaTuna

Setting springs may sound like a good idea but usually it is not unless it is done by a pro like Jim Maccari and set for a specific spring and gun with all of the known specs. There are a couple of people out there that sell so called tune kits with tune parts and springs that are preset. It may make the spring a little easier to install and reduce the first time cocking effort but is rarely and almost impossible to set at peak performance. Unless you know exactly what the spring set height is, it’s usually counter productive and causes loss of efficiency.

There are many variables to take into consideration when setting springs for maximum efficiency including spring wire diameter, coil count, tophat, piston travel to lockup, and spacers if any (also known as “pushing” the spring). Even then it is not perfect.

The most perfect way to set a spring is to let the gun itself do it and it will never set wrong whether you are replacing a new OEM spring or a custom spring as long as you have it assembled properly with the correct tophat and any spacing that you want to do. (If you understand spring spacing and coil bind)

Ok….so…. just how do you/I set a spring in a Springer. It’s very simple. Just assemble it, cock it, close the cocking lever or break and let it set for a minute or so with no pellet in it. Don’t want an accidental discharge in the event that something may be wrong with the gun or incorrectly assembled. You will notice that it will be heavy cocking the first time but that’s normal. Now, open the breech, put a pellet in it and then shoot it.

What happened? When you cock the gun and the sear locks into place, you will be compressing the spring to its maximum coil set height and the spring will set itself exactly where it needs to be. After the gun has been cocked the first time, you will find that it will now be considerably easier to cock as the spring has now been basically set. After 3-4 shots, it will be set…kinda like self adjusting.

[harvey_s]

Can't see why you would and doubt you have the equipment to do it even if you wanted to...
If you had 2 springs working in tandem via a linkage you might want to, to stop one side working harder than the other, but for a single spring I cannot see the point.

[Troubledshooter]

I think Garvin's post #6 says it all.

I have never 'scragged' or re-set a spring before fitting.

[vbull]

Thanks for all the advice and PM's. I'll do as Garvin suggests and let the gun set the spring.

[wonky donky]

I have springs made to my own specification from high quality wire, one thing I insist on is having them double scragged at the factory.

The reason for the double scragg is so minimum set takes place.

[vbull]

What's a double scrag ?

[Benelli B76]

What's a double scrag ?

Probably a waste of time.Don't think you would notice the difference.

Baz

[TonyL]

Excellent article on mainspring quality etc by Jim Tyler in this money's Airgun World.

Read; then decide.

I suppose, if you're not aware if it's been done at the factory, better to do it. Easier to set the gun up post build that way?

[flatrajectory]

I believe the main reason for scragging is to weed out a bad spring. If the spring shrinks considerably after scragging then it will not last long in your rifle. Also, once the spring has set after scragging you can then accurately work out any preload required.
Pete.

[Benelli B76]

To me it is like turning an energetic youth into an old man overnight.

Baz